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Neben den naturharten Kupferwerkstoffen spielen aushärtbare Kupferlegierungen
als Trägerwerkstoffe für elektrische Kontakte eine wichtige Rolle.
Bei den aushärtbaren Legierungen können durch eine geeignete Wärmebehandlung
fein verteilte Ausscheidungen einer zweiten Phase erzeugt werden,
die die Festigkeit des Werkstoffes deutlich erhöhen.
====<!--5.1.6.1-->Kupfer-Beryllium-Legierungen (Berylliumbronze)====
Voraussetzung für die Aushärtbarkeit der CuBe-Werkstoffe ist die mit sinkender
Temperatur rasch abnehmende Löslichkeit des Berylliums im Kupfer. Wie aus
dem Zustandsschaubild für CuBe ersichtlich, sind bei ca. 780°C 2,4 Massen-%
Be in Kupfer löslich <xr id="fig:Phase_diagram_of_copperberyllium_with_temperature_ranges_for_brazing_and_annealing_treatments"/><!--(Fig. 5.28)-->. In diesem Temperaturbereich wärmebehandelte
CuBe-Legierungen sind homogen („lösungsglühen“). Der homogene Zustand
kann durch schnelles Abkühlen auf Raumtemperatur eingefroren werden („abschrecken“).
Durch die anschließende Wärmebehandlung bei einer Temperatur
von 325°C wird die gewünschte Ausscheidungshärtung erreicht, die einen
deutlichen Anstieg der Festigkeit und der elektrischen Leitfähigkeit von CuBe
bewirkt <xr id="tab:Physical_Properties_of_Selected_Copper_Beryllium_Alloys"/><!--(Tab. 5.17)-->. Die erreichbaren Festigkeits- und Härtewerte sind abhängig
von der Glühtemperatur und Glühdauer sowie vom Umformgrad (Tab. 5.18) und
<xr id="tab:Mechanical Properties of Selected Copper-Beryllium Alloys"/><!--(Table 5.18)--> and [[#figures7|(Figs. 43 – 75)]]<!--(Figs. 5.29 - 5.31)-->.
Von den aushärtbaren Kupferlegierungen haben CuBe-Werkstoffe, vor allem
CuBe2 und CuBe1,7 für stromführende Kontaktfedern wegen ihrer herausragenden
mechanischen Eigenschaften eine besondere Bedeutung erlangt.
Daneben sind noch die Werkstoffe CuCo2Be und CuNi2Be zu erwähnen, die
bei mittleren Festigkeitswerten eine relativ hohe elektrische Leitfähigkeit
aufweisen.
CuBe-Legierungen sind als aushärtbare Halbzeuge in verschiedenen Lieferzuständen
erhältlich. Daneben können CuBe-Halbzeuge mit geringen Einbußen
hinsichtlich der Festigkeitseigenschaften im „werksvergüteten“ Zustand eingesetzt
werden. In diesem Falle wurde das Halbzeug bereits beim Hersteller
ausscheidungsgehärtet.
Da Beryllium in der EU-67/548 als kanzerogen eingestuft ist, wird bei einer
Reihe von Legierungen versucht, das Eigenschaftsspektrum der bewährten
CuBe1,7- und CuBe2-Werkstoffe wenigstens näherungsweise auch mit einem
geringeren Be-Anteil zu erreichen. Auch die Entwicklung weiterer ausscheidungshärtender
Kupfer-Legierungen ohne toxische bzw. deklarationspfichtige
Elemente z.B. CuNiCoSi zielt in Richtung CuBe-Ersatz.
<div id="figures7">
<xr id="fig:Phase_diagram_of_copperberyllium_with_temperature_ranges_for_brazing_and_annealing_treatments"/><!--Fig. 5.28:--> Zustandsdiagramm Kupfer-Beryllium mit Temperaturbereichen für Hartlötungen und Wärmebehandlungen
<xr id="fig:Precipitation_hardening_of_CuBe2_at_325°C_after_different_cold_working"/><!--Fig. 5.29:--> Aushärtung von CuBe2 bei 325°C nach unterschiedlicher Kaltumformung
<xr id="fig:Precipitation_hardening_of_CuBe2_(soft)_at_325°C"/><!--Fig. 5.30:--> Precipitation hardening of CuBe2 (soft) at 325°C
<xr id="fig:Precipitation_hardening_of_CuBe2_(half hard)_at_different_annealing_temperatures"/><!--Fig. 5.31:--> Precipitation hardening of CuBe2 (half hard) at different annealing temperatures
</div>
<div class="multiple-images">
<figure id="fig:Phase_diagram_of_copperberyllium_with_temperature_ranges_for_brazing_and_annealing_treatments">
[[File:Phase diagram of copper beryllium with temperature ranges.jpg|left|thumb|<caption>Zustandsdiagramm Kupfer-Beryllium mit Temperaturbereichen für Hartlötungen und Wärmebehandlungen</caption>]]
</figure>
<figure id="fig:Precipitation_hardening_of_CuBe2_at_325°C_after_different_cold_working">
[[File:Precipitation hardening of CuBe2 at 325C.jpg|left|thumb|<caption>Aushärtung von CuBe2 bei 325°C nach unterschiedlicher Kaltumformung</caption>]]
</figure>
<figure id="fig:Precipitation_hardening_of_CuBe2_(soft)_at_325°C">
[[File:Precipitation hardening of CuBe2 (soft) at 325C.jpg|left|thumb|<caption>Precipitation hardening of CuBe2 (soft) at 325°C</caption>]]
</figure>
<figure id="fig:Precipitation_hardening_of_CuBe2_(half hard)_at_different_annealing_temperatures">
[[File:Precipitation hardening of CuBe2 half hard.jpg|left|thumb|<caption>Precipitation hardening of CuBe2 (half hard) at different annealing temperatures</caption>]]
</figure>
</div>
<div class="clear"></div>
<figtable id="tab:Physical_Properties_of_Selected_Copper_Beryllium_Alloys">
<caption>'''<!--Table 5.17:-->Physical Properties of Selected Copper-Beryllium Alloys'''</caption>
{| class="twocolortable" style="text-align: left; font-size: 12px"
|-
!Material<br />Designation<br />EN UNS
!Composition<br />[wt%]
!Density<br />[g/cm<sup>3</sup>]
!colspan="2" style="text-align:center"|Electrical<br />Conductivity
!Electrical<br />Resistivity<br />[μΩ·cm]
!Thermal<br />Conductivity<br />[W/(m·K)]
!Coeff. of Linear<br />Thermal<br />Expansion<br />[10<sup>-6</sup>/K]
!Modulus of<br />Elasticity<br />[GPa]
!Softening Temperature<br />(approx. 10% loss in<br />strength)<br />[°C]
!Melting<br />Temp Range<br />[°C]
|-
!
!
!
![MS/m]
![% IACS]
!
!
!
!
!
!
|-
|CuBe1.7<br />CW100C<br />C17000
|Be 1.6 - 1.8<br />Co 0.3<br />Ni 0.3<br />Cu Rest
|8.4
|8 - 9<sup>a</sup><br />12 - 13<sup>b</sup><br />11<sup>c</sup>
|14 - 16<br />21 - 22<br />19
|11 - 12.5<sup>a</sup><br />7.7 - 8.3<sup>b</sup><br />9.1<sup>c</sup>
|110
|17
|125<sup>a</sup><br />135<sup>b</sup>
|ca. 380
|890 - 1000
|-
|CuBe2<br />CW101C<br />C17200
|Be 1.8 - 2.1<br />Co 0.3<br />Ni 0.3<br />Cu Rest
|8.3
|8 - 9<sup>a</sup><br />12 - 13<sup>b</sup><br />11<sup>c</sup>
|14 - 16<br />21 - 22<br />19
|11 - 12.5<sup>a</sup><br />7.7 - 8.3<sup>b</sup><br />9.1<sup>c</sup>
|110
|17
|125<sup>a</sup><br />135<sup>b</sup>
|ca. 380
|870 - 980
|-
|CuCo2Be<br />CW104C<br />C17500
|Co 2.0 - 2.8<br />Be 0.4 - 0.7<br />Ni 0.3<br />Cu Rest
|8.8
|11 - 14<sup>a</sup><br />25 - 27<sup>b</sup><br />27 - 34<sup>c</sup>
|19 - 24<br />43 - 47<br />47 - 59
|7.1 - 9.1<sup>a</sup><br />3.7 - 4.0<sup>b</sup><br />2.9<sup>c</sup>
|210
|18
|131<sup>a</sup><br />138<sup>b</sup>
|ca. 450
|1030 - 1070
|-
|CuNi2Be<br />CW110C<br />C17510
|Ni 1.4 - 2.2<br />Be 0.2 - 0.6<br />Co 0.3<br />Cu Rest
|8.8
|11 - 14<sup>a</sup><br />25 - 27<sup>b</sup><br />27 - 34<sup>c</sup>
|19 - 24<br />43 - 47<br />47 - 59
|7.1 - 9.1<sup>a</sup><br />3.7 - 4.0<sup>b</sup><br />2.9<sup>c</sup>
|230
|18
|131<sup>a</sup><br />138<sup>b</sup>
|ca. 480
|1060 - 1100
|}
</figtable>
<sup>a</sup>solution annealed, and cold rolled<br />
<sup>b</sup>solution annealed, cold rolled, and precipitation hardened<br />
<sup>c</sup>solution annealed, cold rolled, and precipitation hardened at mill (mill hardened)
<figtable id="tab:Mechanical Properties of Selected Copper-Beryllium Alloys">
<caption>'''<!--Table 5.18:-->Mechanical Properties of Selected Copper-Beryllium Alloys'''</caption>
{| class="twocolortable" style="text-align: left; font-size: 12px"
|-
!Material
!Hardness<br />Condition
!Tensile Strength R<sub>m</sub><br />[MPa]
!0,2% Yield Strength<br />R<sub>p02</sub><br />[MPa]
!Elongation<br />A<sub>50</sub><br />[%]
!Vickers<br />Hardness<br />HV
!Bend Radius<sup>1)</sup><br />perpendicular to<br />rolling direction
!Bend Radius<sup>1)</sup><br />parallel to<br />rolling direction
!Spring Bending<br />Limit σ<sub>FB</sub><br />[MPa]
!Spring Fatigue<br />Limit σ<sub>BW</sub><br />[MPa]
|-
|CuBe1,7
|R 390<sup>a</sup><br />R 680<sup>a</sup><br />R 1030<sup>b</sup><br />R 1240<sup>b</sup><br />R 680<sup>c</sup><br />R 1100<sup>c</sup>
|380 -520<br />680 - 820<br />1030 - 1240<br />1240 - 1380<br />680 - 750<br />1100 - 1200
|≥ 180<br />≥ 600<br />≥ 900<br />≥ 1070<br />≥ 480<br />≥ 930
|35<br />2<br />3<br />1<br />18<br />3
|80 - 135<br />210 - 250<br />330 - 380<br />360 - 420<br />220 - 350<br />330 - 370
|0 x t<br />1 x t<br />1 x t<br /><br />1 x t<br />6 x t
|0 x t<br />3 x t<br />1.5 x t<br /><br />1 x t<br />10 x t
| <br /> <br />700<br />1000<br />390<br />790
| <br /> <br />260<br />280<br /> <br />260
|-
|CuBe2
|R 410<sup>a</sup><br />R 690<sup>a</sup><br />R 1140<sup>b</sup><br />R 1310<sup>b</sup><br />R 690<sup>c</sup><br />R 1200<sup>c</sup>
|410 -540<br />690 - 820<br />1140 - 1310<br />1310 - 1480<br />690 - 760<br />1200 - 1320
|≥ 190<br />≥ 650<br />≥ 1000<br />≥ 1150<br />≥ 480<br />≥ 1030
|35<br />2<br />3<br />1<br />18<br />3
|90 - 140<br />215 - 260<br />350 - 400<br />380 - 450<br />220 - 250<br />360 - 410
|0 x t<br />1 x t<br /> <br /> <br />1 x t<br />5 x t
|0 x t<br />3 x t<br /> <br /> <br />1.5 x t<br />10 x t
| <br /> <br />800<br />1040<br />400<br />900
| <br /> <br />270<br />300<br /> <br />280
|-
|CuCo2Be<br />CuNi2Be
|R 250<sup>a</sup><br />R 550<sup>a</sup><br />R 650<sup>b</sup><br />R 850<sup>b</sup><br />R 520<sup>c</sup>
|250 - 380<br />550 - 700<br />650 - 820<br />850 - 1000<br />520 - 620
|≥ 140<br />≥ 450<br />≥ 520<br />≥ 750<br />≥ 340
|20<br />2<br />10<br />1<br />5
|60 - 90<br />160 - 200<br />195 - 230<br />240 - 290<br />150 - 180
|0 x t<br />3 x t<br />1 x t<br />3 x t<br />1 x t
|0 x t<br /> <br />1 x t<br />3.5 x t<br />1 x t
| <br /> <br />360<br />650<br />300
| <br /> <br />220<br />250<br />210
|}
</figtable>
<sup>1)</sup> t: Strip thickness max. 0.5 mm<br />
<sup>a</sup>solution annealed, and cold rolled<br />
<sup>b</sup>solution annealed, cold rolled, and precipitation hardened<br />
<sup>c</sup>solution annealed, cold rolled, and precipitation hardened at mill (mill hardened)
====<!--5.1.6.2-->Other Precipitation Hardening Copper Alloys====
=====<!--5.1.6.2.1-->Copper-Chromium Alloys=====
As the phase diagram shows, copper-chromium has a similar hardening profile compared to CuBe <xr id="fig:Copper corner of the copper-chromium phase diagram for up to 0.8 wt% chromium"/><!--(Fig. 5.32)-->. In the hardened stage CuCr has limitations to work hardening. Compared to copper it has a better temperature stability with good electrical conductivity. Hardness and electrical conductivity as a function of cold working and precipitation hardening conditions are illustrated in [[#figures8|(Figs. 6 – 9)]]<!--Figs. 5.33-5.35-->, <xr id="tab:Physical Properties of Other Precipitation Hardening Copper Alloys"/><!--(Tables 5.19)--> and <xr id="tab:Mechanical Properties of Other Precipitation Hardening Copper Alloys"/><!--(Tab. 5.20)-->.
Copper-chromium materials are especially suitable for use as electrodes for resistance welding. During brazing the loss in hardness is limited if low melting brazing alloys and reasonably short heating times are used.
<div id="figures5">
<xr id="fig:Copper corner of the copper-chromium phase diagram for up to 0.8 wt% chromium"/><!--Fig. 5.32:--> Copper corner of the copper-chromium phase diagram for up to 0.8 wt% chromium
<xr id="fig:Softening of precipitation hardened and subsequently cold worked CuCr1"/><!--Fig. 5.33:--> Softening of precipitation-hardened and subsequently cold worked CuCr1 after 4hrs annealing
<xr id="fig:Electrical conductivity of precipitation hardened CuCr 0.6"/><!--Fig. 5.34 a:--> Electrical conductivity of precipitation hardened CuCr 0.6 as a function of annealing conditions
<xr id="fig:Hardness of precipitation hardened CuCr 0.6"/><!--Fig. 5.34 b:--> Hardness of precipitation hardened CuCr 0.6 as a function of annealing conditions
<xr id="fig:Electrical conductivity and hardness of precipitation hardened CuCr 0.6"/><!--Fig. 5.35:--> Electrical conductivity and hardness of precipitation hardened CuCr 0.6 after cold working
</div>
<div class="multiple-images">
<figure id="fig:Copper corner of the copper-chromium phase diagram for up to 0.8 wt% chromium">
[[File:Copper corner of the copper chromium phase diagram.jpg|left|thumb|<caption>Copper corner of the copper-chromium phase diagram for up to 0.8 wt% chromium</caption>]]
</figure>
<figure id="fig:Softening of precipitation hardened and subsequently cold worked CuCr1">
[[File:Softening of precipitation hardened and subsequently cold worked CuCr1.jpg|left|thumb|<caption>Softening of precipitation-hardened and subsequently cold worked CuCr1 after 4hrs annealing</caption>]]
</figure>
<figure id="fig:Electrical conductivity of precipitation hardened CuCr 0.6">
[[File:Electrical conductivity of precipitation hardened CuCr 0.6.jpg|left|thumb|<caption>Electrical conductivity of precipitation hardened CuCr 0.6 as a function of annealing conditions</caption>]]
</figure>
<figure id="fig:Hardness of precipitation hardened CuCr 0.6">
[[File:Hardness of precipitation hardened CuCr 0.6.jpg|left|thumb|<caption>Hardness of precipitation hardened CuCr 0.6 as a function of annealing conditions</caption>]]
</figure>
<figure id="fig:Electrical conductivity and hardness of precipitation hardened CuCr 0.6">
[[File:Electrical conductivity and hardness of precipitation hardened CuCr 0.6.jpg|left|thumb|<caption>Electrical conductivity and hardness of precipitation hardened CuCr 0.6 after cold working</caption>]]
</figure>
</div>
<div class="clear"></div>
<figtable id="tab:Physical Properties of Other Precipitation Hardening Copper Alloys">
<caption>'''<!--Table 5.19:-->Physical Properties of Other Precipitation Hardening Copper Alloys'''</caption>
{| class="twocolortable" style="text-align: left; font-size: 12px"
|-
!Material<br />Designation<br />EN UNS
!Composition<br />[wt%]
!Density<br />[g/cm<sup>3</sup>]
!colspan="2" style="text-align:center"|Electrical<br />Conductivity
!Electrical<br />Resistivity<br />[μΩ·cm]
!Thermal<br />Conductivity<br />[W/(m·K)]
!Coeff. of Linear<br />Thermal<br />Expansion<br />[10<sup>-6</sup>/K]
!Modulus of<br />Elasticity<br />[GPa]
!Softening Temperature<br />(approx. 10% loss in<br />strength)<br />[°C]
!Melting<br />Temp Range<br />[°C]
|-
!
!
!
![MS/m]
![% IACS]
!
!
!
!
!
!
|-
|CuCr
|Cr 0.3 - 1.2<br />Cu Rest
|8.89
|26<sup>a</sup><br />48<sup>b</sup>
|45<sup>a</sup><br />83<sup>b</sup>
|3.8<sup>a</sup><br />2.1<sup>b</sup>
|170<sup>a</sup><br />315<sup>b</sup>
|17
|112
|ca. 450
|980 - 1080
|-
|CuZr
|Zr 0.1 - 0.3<br />Cu Rest
|8.9
|35<sup>a</sup><br />52<sup>b</sup>
|60<sup>a</sup><br />90<sup>b</sup>
|2.9<sup>a</sup><br />1.9<sup>b</sup>
|340<sup>a</sup>
|16
|135
|ca. 500
|1020 - 1080
|-
|CuCr1Zr<br />CW106C<br />C18150
|Cr 0.5 - 1.2<br />Zr 0.03 - 0.3<br />Cu Rest
|8.92
|20<sup>a</sup><br />43<sup>b</sup>
|34<sup>a</sup><br />74<sup>b</sup>
|5.0<sup>a</sup><br />2.3<sup>b</sup>
|170<sup>a</sup><br />310 - 330<sup>b</sup>
|16
|110<sup>a</sup><br />130<sup>b</sup>
|ca. 500
|1070 - 1080
|}
</figtable>
<sup>a</sup>solution annealed, and cold rolled<br />
<sup>b</sup>solution annealed, cold rolled, and precipitation hardened<br />
<figtable id="tab:Mechanical Properties of Other Precipitation Hardening Copper Alloys">
<caption>'''<!--Table 5.20:-->Mechanical Properties of Other Precipitation Hardening Copper Alloys'''</caption>
<table class="twocolortable">
<tr><th><p class="s16">Material</p></th><th><p class="s16">Hardness</p><p class="s16">Condi- tion</p></th><th><p class="s16">Tensile</p><p class="s16">Strength R<span class="s18">m</span></p><p class="s16">[MPa]</p></th><th><p class="s16">0,2% Yield</p><p class="s16">Strength R<span class="s18">p02</span></p><p class="s16">[MPa]</p></th><th><p class="s16">Elongation</p><p class="s16">A50</p><p class="s16">[%]</p></th><th><p class="s16">Vickers</p><p class="s16">Hardness</p><p class="s16">HV</p></th><th><p class="s16">Spring Bending</p><p class="s16">Limit <span class="s19">F</span><span class="s18">FB </span>[MPa]</p></th></tr><tr><td><p class="s16">CuCr</p></td><td><p class="s16">R 230<span class="s18">a</span></p><p class="s16">R 400<span class="s18">a </span>R 450<span class="s18">b </span>R 550<span class="s18">b</span></p></td><td><p class="s33">><span class="s16"> 230</span></p><p class="s33">><span class="s16"> 400</span></p><p class="s33">><span class="s16"> 450</span></p><p class="s33">><span class="s16"> 550</span></p></td><td><p class="s33">><span class="s16"> 80</span></p><p class="s33">><span class="s16"> 295</span></p><p class="s33">><span class="s16"> 325</span></p><p class="s33">><span class="s16"> 440</span></p></td><td><p class="s16">30</p><p class="s16">10</p><p class="s16">10</p><p class="s16">8</p></td><td><p class="s33">><span class="s16"> 55</span></p><p class="s33">><span class="s16"> 120</span></p><p class="s33">><span class="s16"> 130</span></p><p class="s33">><span class="s16"> 150</span></p></td><td><p class="s16">350</p></td></tr><tr><td><p class="s16">CuZr</p></td><td><p class="s16">R 260<span class="s18">a</span></p><p class="s16">R 370<span class="s18">a </span>R 400<span class="s18">b </span>R 420<span class="s18">b</span></p></td><td><p class="s33">><span class="s16"> 260</span></p><p class="s33">><span class="s16"> 370</span></p><p class="s33">><span class="s16"> 400</span></p><p class="s33">><span class="s16"> 420</span></p></td><td><p class="s33">><span class="s16"> 100</span></p><p class="s33">><span class="s16"> 270</span></p><p class="s33">><span class="s16"> 280</span></p><p class="s33">><span class="s16"> 400</span></p></td><td><p class="s16">35</p><p class="s16">12</p><p class="s16">12</p><p class="s16">10</p></td><td><p class="s33">><span class="s16"> 55</span></p><p class="s33">><span class="s16"> 100</span></p><p class="s33">><span class="s16"> 105</span></p><p class="s33">><span class="s16"> 115</span></p></td><td><p class="s16">280</p></td></tr><tr><td><p class="s16">CuCr1Zr</p></td><td><p class="s16">R 200<span class="s18">a</span></p><p class="s16">R 400<span class="s18">b</span></p><p class="s16">R 450<span class="s18">b</span></p></td><td><p class="s33">><span class="s16"> 200</span></p><p class="s33">><span class="s16"> 400</span></p><p class="s33">><span class="s16"> 450</span></p></td><td><p class="s33">><span class="s16"> 60</span></p><p class="s33">><span class="s16"> 210</span></p><p class="s33">><span class="s16"> 360</span></p></td><td><p class="s16">30</p><p class="s16">12</p><p class="s16">10</p></td><td><p class="s33">><span class="s16"> 70</span></p><p class="s33">><span class="s16"> 140</span></p><p class="s33">><span class="s16"> 155</span></p></td><td><p class="s16">420</p></td></tr></table>
</figtable>
=====<!--5.1.6.2.2-->Copper-Zirconium Alloys=====
The solubility of Zirconium in copper is 0.15 wt% Zr at the eutectic temperature of 980°C <xr id="fig:Copper corner of the copper zirconium for up to 0.5-wt zirconium"/><!--(Fig. 5.36)-->. Copper-zirconium materials have a similar properties spectrum compared to the one for copper-chromium materials. At room temperature the mechanical properties of copper-zirconium are less suitable than those of copper chromium, its temperature stability is however at least the same.
=====<!--5.1.6.2.3-->Copper-Chromium-Zirconium Alloys=====
The earlier used CuCr and CuZr materials have been partially replaced over the years by the capitation hardening three materials alloy CuCr1Zr. This material exhibits high mechanical strength at elevated temperatures and good oxidation resistance as well as high softening temperatures. In its hardened condition CuCr1Zr has also a high electrical conductivity <xr id="fig:Softening of CuCr1Zr after 1hr annealing"/><!--(Bild 5.37)-->. Their usage extends from mechanically and thermally highly stressed parts such as contact tulips in high voltage switchgear to electrodes for resistance welding.
<xr id="fig:Copper corner of the copper zirconium for up to 0.5-wt zirconium"/><!--Fig. 5.36:--> Copper corner of the copper- zirconium for up to 0.5 wt% zirconium
<xr id="fig:Softening of CuCr1Zr after 1hr annealing"/><!--Fig. 5.37:--> Softening of CuCr1Zr after 1 hr annealing and after 90% cold working
<div class="multiple-images">
<figure id="fig:Copper corner of the copper zirconium for up to 0.5-wt zirconium">
[[File:Copper corner of the copper zirconium for up to 0.5-wt zirconium.jpg|right|thumb|Copper corner of the copper- zirconium for up to 0.5 wt% zirconium]]
</figure>
<figure id="fig:Softening of CuCr1Zr after 1hr annealing">
[[File:Softening of CuCr1Zr after 1hr annealing.jpg|right|thumb|Softening of CuCr1Zr after 1 hr annealing and after 90% cold working]]
</figure>
</div>
<div class="clear"></div>
==Referenzen==
[[Trägerwerkstoffe#Referenzen|Referenzen]]
[[en:Precipitation_Hardening_Copper_Alloys]]
als Trägerwerkstoffe für elektrische Kontakte eine wichtige Rolle.
Bei den aushärtbaren Legierungen können durch eine geeignete Wärmebehandlung
fein verteilte Ausscheidungen einer zweiten Phase erzeugt werden,
die die Festigkeit des Werkstoffes deutlich erhöhen.
====<!--5.1.6.1-->Kupfer-Beryllium-Legierungen (Berylliumbronze)====
Voraussetzung für die Aushärtbarkeit der CuBe-Werkstoffe ist die mit sinkender
Temperatur rasch abnehmende Löslichkeit des Berylliums im Kupfer. Wie aus
dem Zustandsschaubild für CuBe ersichtlich, sind bei ca. 780°C 2,4 Massen-%
Be in Kupfer löslich <xr id="fig:Phase_diagram_of_copperberyllium_with_temperature_ranges_for_brazing_and_annealing_treatments"/><!--(Fig. 5.28)-->. In diesem Temperaturbereich wärmebehandelte
CuBe-Legierungen sind homogen („lösungsglühen“). Der homogene Zustand
kann durch schnelles Abkühlen auf Raumtemperatur eingefroren werden („abschrecken“).
Durch die anschließende Wärmebehandlung bei einer Temperatur
von 325°C wird die gewünschte Ausscheidungshärtung erreicht, die einen
deutlichen Anstieg der Festigkeit und der elektrischen Leitfähigkeit von CuBe
bewirkt <xr id="tab:Physical_Properties_of_Selected_Copper_Beryllium_Alloys"/><!--(Tab. 5.17)-->. Die erreichbaren Festigkeits- und Härtewerte sind abhängig
von der Glühtemperatur und Glühdauer sowie vom Umformgrad (Tab. 5.18) und
<xr id="tab:Mechanical Properties of Selected Copper-Beryllium Alloys"/><!--(Table 5.18)--> and [[#figures7|(Figs. 43 – 75)]]<!--(Figs. 5.29 - 5.31)-->.
Von den aushärtbaren Kupferlegierungen haben CuBe-Werkstoffe, vor allem
CuBe2 und CuBe1,7 für stromführende Kontaktfedern wegen ihrer herausragenden
mechanischen Eigenschaften eine besondere Bedeutung erlangt.
Daneben sind noch die Werkstoffe CuCo2Be und CuNi2Be zu erwähnen, die
bei mittleren Festigkeitswerten eine relativ hohe elektrische Leitfähigkeit
aufweisen.
CuBe-Legierungen sind als aushärtbare Halbzeuge in verschiedenen Lieferzuständen
erhältlich. Daneben können CuBe-Halbzeuge mit geringen Einbußen
hinsichtlich der Festigkeitseigenschaften im „werksvergüteten“ Zustand eingesetzt
werden. In diesem Falle wurde das Halbzeug bereits beim Hersteller
ausscheidungsgehärtet.
Da Beryllium in der EU-67/548 als kanzerogen eingestuft ist, wird bei einer
Reihe von Legierungen versucht, das Eigenschaftsspektrum der bewährten
CuBe1,7- und CuBe2-Werkstoffe wenigstens näherungsweise auch mit einem
geringeren Be-Anteil zu erreichen. Auch die Entwicklung weiterer ausscheidungshärtender
Kupfer-Legierungen ohne toxische bzw. deklarationspfichtige
Elemente z.B. CuNiCoSi zielt in Richtung CuBe-Ersatz.
<div id="figures7">
<xr id="fig:Phase_diagram_of_copperberyllium_with_temperature_ranges_for_brazing_and_annealing_treatments"/><!--Fig. 5.28:--> Zustandsdiagramm Kupfer-Beryllium mit Temperaturbereichen für Hartlötungen und Wärmebehandlungen
<xr id="fig:Precipitation_hardening_of_CuBe2_at_325°C_after_different_cold_working"/><!--Fig. 5.29:--> Aushärtung von CuBe2 bei 325°C nach unterschiedlicher Kaltumformung
<xr id="fig:Precipitation_hardening_of_CuBe2_(soft)_at_325°C"/><!--Fig. 5.30:--> Precipitation hardening of CuBe2 (soft) at 325°C
<xr id="fig:Precipitation_hardening_of_CuBe2_(half hard)_at_different_annealing_temperatures"/><!--Fig. 5.31:--> Precipitation hardening of CuBe2 (half hard) at different annealing temperatures
</div>
<div class="multiple-images">
<figure id="fig:Phase_diagram_of_copperberyllium_with_temperature_ranges_for_brazing_and_annealing_treatments">
[[File:Phase diagram of copper beryllium with temperature ranges.jpg|left|thumb|<caption>Zustandsdiagramm Kupfer-Beryllium mit Temperaturbereichen für Hartlötungen und Wärmebehandlungen</caption>]]
</figure>
<figure id="fig:Precipitation_hardening_of_CuBe2_at_325°C_after_different_cold_working">
[[File:Precipitation hardening of CuBe2 at 325C.jpg|left|thumb|<caption>Aushärtung von CuBe2 bei 325°C nach unterschiedlicher Kaltumformung</caption>]]
</figure>
<figure id="fig:Precipitation_hardening_of_CuBe2_(soft)_at_325°C">
[[File:Precipitation hardening of CuBe2 (soft) at 325C.jpg|left|thumb|<caption>Precipitation hardening of CuBe2 (soft) at 325°C</caption>]]
</figure>
<figure id="fig:Precipitation_hardening_of_CuBe2_(half hard)_at_different_annealing_temperatures">
[[File:Precipitation hardening of CuBe2 half hard.jpg|left|thumb|<caption>Precipitation hardening of CuBe2 (half hard) at different annealing temperatures</caption>]]
</figure>
</div>
<div class="clear"></div>
<figtable id="tab:Physical_Properties_of_Selected_Copper_Beryllium_Alloys">
<caption>'''<!--Table 5.17:-->Physical Properties of Selected Copper-Beryllium Alloys'''</caption>
{| class="twocolortable" style="text-align: left; font-size: 12px"
|-
!Material<br />Designation<br />EN UNS
!Composition<br />[wt%]
!Density<br />[g/cm<sup>3</sup>]
!colspan="2" style="text-align:center"|Electrical<br />Conductivity
!Electrical<br />Resistivity<br />[μΩ·cm]
!Thermal<br />Conductivity<br />[W/(m·K)]
!Coeff. of Linear<br />Thermal<br />Expansion<br />[10<sup>-6</sup>/K]
!Modulus of<br />Elasticity<br />[GPa]
!Softening Temperature<br />(approx. 10% loss in<br />strength)<br />[°C]
!Melting<br />Temp Range<br />[°C]
|-
!
!
!
![MS/m]
![% IACS]
!
!
!
!
!
!
|-
|CuBe1.7<br />CW100C<br />C17000
|Be 1.6 - 1.8<br />Co 0.3<br />Ni 0.3<br />Cu Rest
|8.4
|8 - 9<sup>a</sup><br />12 - 13<sup>b</sup><br />11<sup>c</sup>
|14 - 16<br />21 - 22<br />19
|11 - 12.5<sup>a</sup><br />7.7 - 8.3<sup>b</sup><br />9.1<sup>c</sup>
|110
|17
|125<sup>a</sup><br />135<sup>b</sup>
|ca. 380
|890 - 1000
|-
|CuBe2<br />CW101C<br />C17200
|Be 1.8 - 2.1<br />Co 0.3<br />Ni 0.3<br />Cu Rest
|8.3
|8 - 9<sup>a</sup><br />12 - 13<sup>b</sup><br />11<sup>c</sup>
|14 - 16<br />21 - 22<br />19
|11 - 12.5<sup>a</sup><br />7.7 - 8.3<sup>b</sup><br />9.1<sup>c</sup>
|110
|17
|125<sup>a</sup><br />135<sup>b</sup>
|ca. 380
|870 - 980
|-
|CuCo2Be<br />CW104C<br />C17500
|Co 2.0 - 2.8<br />Be 0.4 - 0.7<br />Ni 0.3<br />Cu Rest
|8.8
|11 - 14<sup>a</sup><br />25 - 27<sup>b</sup><br />27 - 34<sup>c</sup>
|19 - 24<br />43 - 47<br />47 - 59
|7.1 - 9.1<sup>a</sup><br />3.7 - 4.0<sup>b</sup><br />2.9<sup>c</sup>
|210
|18
|131<sup>a</sup><br />138<sup>b</sup>
|ca. 450
|1030 - 1070
|-
|CuNi2Be<br />CW110C<br />C17510
|Ni 1.4 - 2.2<br />Be 0.2 - 0.6<br />Co 0.3<br />Cu Rest
|8.8
|11 - 14<sup>a</sup><br />25 - 27<sup>b</sup><br />27 - 34<sup>c</sup>
|19 - 24<br />43 - 47<br />47 - 59
|7.1 - 9.1<sup>a</sup><br />3.7 - 4.0<sup>b</sup><br />2.9<sup>c</sup>
|230
|18
|131<sup>a</sup><br />138<sup>b</sup>
|ca. 480
|1060 - 1100
|}
</figtable>
<sup>a</sup>solution annealed, and cold rolled<br />
<sup>b</sup>solution annealed, cold rolled, and precipitation hardened<br />
<sup>c</sup>solution annealed, cold rolled, and precipitation hardened at mill (mill hardened)
<figtable id="tab:Mechanical Properties of Selected Copper-Beryllium Alloys">
<caption>'''<!--Table 5.18:-->Mechanical Properties of Selected Copper-Beryllium Alloys'''</caption>
{| class="twocolortable" style="text-align: left; font-size: 12px"
|-
!Material
!Hardness<br />Condition
!Tensile Strength R<sub>m</sub><br />[MPa]
!0,2% Yield Strength<br />R<sub>p02</sub><br />[MPa]
!Elongation<br />A<sub>50</sub><br />[%]
!Vickers<br />Hardness<br />HV
!Bend Radius<sup>1)</sup><br />perpendicular to<br />rolling direction
!Bend Radius<sup>1)</sup><br />parallel to<br />rolling direction
!Spring Bending<br />Limit σ<sub>FB</sub><br />[MPa]
!Spring Fatigue<br />Limit σ<sub>BW</sub><br />[MPa]
|-
|CuBe1,7
|R 390<sup>a</sup><br />R 680<sup>a</sup><br />R 1030<sup>b</sup><br />R 1240<sup>b</sup><br />R 680<sup>c</sup><br />R 1100<sup>c</sup>
|380 -520<br />680 - 820<br />1030 - 1240<br />1240 - 1380<br />680 - 750<br />1100 - 1200
|≥ 180<br />≥ 600<br />≥ 900<br />≥ 1070<br />≥ 480<br />≥ 930
|35<br />2<br />3<br />1<br />18<br />3
|80 - 135<br />210 - 250<br />330 - 380<br />360 - 420<br />220 - 350<br />330 - 370
|0 x t<br />1 x t<br />1 x t<br /><br />1 x t<br />6 x t
|0 x t<br />3 x t<br />1.5 x t<br /><br />1 x t<br />10 x t
| <br /> <br />700<br />1000<br />390<br />790
| <br /> <br />260<br />280<br /> <br />260
|-
|CuBe2
|R 410<sup>a</sup><br />R 690<sup>a</sup><br />R 1140<sup>b</sup><br />R 1310<sup>b</sup><br />R 690<sup>c</sup><br />R 1200<sup>c</sup>
|410 -540<br />690 - 820<br />1140 - 1310<br />1310 - 1480<br />690 - 760<br />1200 - 1320
|≥ 190<br />≥ 650<br />≥ 1000<br />≥ 1150<br />≥ 480<br />≥ 1030
|35<br />2<br />3<br />1<br />18<br />3
|90 - 140<br />215 - 260<br />350 - 400<br />380 - 450<br />220 - 250<br />360 - 410
|0 x t<br />1 x t<br /> <br /> <br />1 x t<br />5 x t
|0 x t<br />3 x t<br /> <br /> <br />1.5 x t<br />10 x t
| <br /> <br />800<br />1040<br />400<br />900
| <br /> <br />270<br />300<br /> <br />280
|-
|CuCo2Be<br />CuNi2Be
|R 250<sup>a</sup><br />R 550<sup>a</sup><br />R 650<sup>b</sup><br />R 850<sup>b</sup><br />R 520<sup>c</sup>
|250 - 380<br />550 - 700<br />650 - 820<br />850 - 1000<br />520 - 620
|≥ 140<br />≥ 450<br />≥ 520<br />≥ 750<br />≥ 340
|20<br />2<br />10<br />1<br />5
|60 - 90<br />160 - 200<br />195 - 230<br />240 - 290<br />150 - 180
|0 x t<br />3 x t<br />1 x t<br />3 x t<br />1 x t
|0 x t<br /> <br />1 x t<br />3.5 x t<br />1 x t
| <br /> <br />360<br />650<br />300
| <br /> <br />220<br />250<br />210
|}
</figtable>
<sup>1)</sup> t: Strip thickness max. 0.5 mm<br />
<sup>a</sup>solution annealed, and cold rolled<br />
<sup>b</sup>solution annealed, cold rolled, and precipitation hardened<br />
<sup>c</sup>solution annealed, cold rolled, and precipitation hardened at mill (mill hardened)
====<!--5.1.6.2-->Other Precipitation Hardening Copper Alloys====
=====<!--5.1.6.2.1-->Copper-Chromium Alloys=====
As the phase diagram shows, copper-chromium has a similar hardening profile compared to CuBe <xr id="fig:Copper corner of the copper-chromium phase diagram for up to 0.8 wt% chromium"/><!--(Fig. 5.32)-->. In the hardened stage CuCr has limitations to work hardening. Compared to copper it has a better temperature stability with good electrical conductivity. Hardness and electrical conductivity as a function of cold working and precipitation hardening conditions are illustrated in [[#figures8|(Figs. 6 – 9)]]<!--Figs. 5.33-5.35-->, <xr id="tab:Physical Properties of Other Precipitation Hardening Copper Alloys"/><!--(Tables 5.19)--> and <xr id="tab:Mechanical Properties of Other Precipitation Hardening Copper Alloys"/><!--(Tab. 5.20)-->.
Copper-chromium materials are especially suitable for use as electrodes for resistance welding. During brazing the loss in hardness is limited if low melting brazing alloys and reasonably short heating times are used.
<div id="figures5">
<xr id="fig:Copper corner of the copper-chromium phase diagram for up to 0.8 wt% chromium"/><!--Fig. 5.32:--> Copper corner of the copper-chromium phase diagram for up to 0.8 wt% chromium
<xr id="fig:Softening of precipitation hardened and subsequently cold worked CuCr1"/><!--Fig. 5.33:--> Softening of precipitation-hardened and subsequently cold worked CuCr1 after 4hrs annealing
<xr id="fig:Electrical conductivity of precipitation hardened CuCr 0.6"/><!--Fig. 5.34 a:--> Electrical conductivity of precipitation hardened CuCr 0.6 as a function of annealing conditions
<xr id="fig:Hardness of precipitation hardened CuCr 0.6"/><!--Fig. 5.34 b:--> Hardness of precipitation hardened CuCr 0.6 as a function of annealing conditions
<xr id="fig:Electrical conductivity and hardness of precipitation hardened CuCr 0.6"/><!--Fig. 5.35:--> Electrical conductivity and hardness of precipitation hardened CuCr 0.6 after cold working
</div>
<div class="multiple-images">
<figure id="fig:Copper corner of the copper-chromium phase diagram for up to 0.8 wt% chromium">
[[File:Copper corner of the copper chromium phase diagram.jpg|left|thumb|<caption>Copper corner of the copper-chromium phase diagram for up to 0.8 wt% chromium</caption>]]
</figure>
<figure id="fig:Softening of precipitation hardened and subsequently cold worked CuCr1">
[[File:Softening of precipitation hardened and subsequently cold worked CuCr1.jpg|left|thumb|<caption>Softening of precipitation-hardened and subsequently cold worked CuCr1 after 4hrs annealing</caption>]]
</figure>
<figure id="fig:Electrical conductivity of precipitation hardened CuCr 0.6">
[[File:Electrical conductivity of precipitation hardened CuCr 0.6.jpg|left|thumb|<caption>Electrical conductivity of precipitation hardened CuCr 0.6 as a function of annealing conditions</caption>]]
</figure>
<figure id="fig:Hardness of precipitation hardened CuCr 0.6">
[[File:Hardness of precipitation hardened CuCr 0.6.jpg|left|thumb|<caption>Hardness of precipitation hardened CuCr 0.6 as a function of annealing conditions</caption>]]
</figure>
<figure id="fig:Electrical conductivity and hardness of precipitation hardened CuCr 0.6">
[[File:Electrical conductivity and hardness of precipitation hardened CuCr 0.6.jpg|left|thumb|<caption>Electrical conductivity and hardness of precipitation hardened CuCr 0.6 after cold working</caption>]]
</figure>
</div>
<div class="clear"></div>
<figtable id="tab:Physical Properties of Other Precipitation Hardening Copper Alloys">
<caption>'''<!--Table 5.19:-->Physical Properties of Other Precipitation Hardening Copper Alloys'''</caption>
{| class="twocolortable" style="text-align: left; font-size: 12px"
|-
!Material<br />Designation<br />EN UNS
!Composition<br />[wt%]
!Density<br />[g/cm<sup>3</sup>]
!colspan="2" style="text-align:center"|Electrical<br />Conductivity
!Electrical<br />Resistivity<br />[μΩ·cm]
!Thermal<br />Conductivity<br />[W/(m·K)]
!Coeff. of Linear<br />Thermal<br />Expansion<br />[10<sup>-6</sup>/K]
!Modulus of<br />Elasticity<br />[GPa]
!Softening Temperature<br />(approx. 10% loss in<br />strength)<br />[°C]
!Melting<br />Temp Range<br />[°C]
|-
!
!
!
![MS/m]
![% IACS]
!
!
!
!
!
!
|-
|CuCr
|Cr 0.3 - 1.2<br />Cu Rest
|8.89
|26<sup>a</sup><br />48<sup>b</sup>
|45<sup>a</sup><br />83<sup>b</sup>
|3.8<sup>a</sup><br />2.1<sup>b</sup>
|170<sup>a</sup><br />315<sup>b</sup>
|17
|112
|ca. 450
|980 - 1080
|-
|CuZr
|Zr 0.1 - 0.3<br />Cu Rest
|8.9
|35<sup>a</sup><br />52<sup>b</sup>
|60<sup>a</sup><br />90<sup>b</sup>
|2.9<sup>a</sup><br />1.9<sup>b</sup>
|340<sup>a</sup>
|16
|135
|ca. 500
|1020 - 1080
|-
|CuCr1Zr<br />CW106C<br />C18150
|Cr 0.5 - 1.2<br />Zr 0.03 - 0.3<br />Cu Rest
|8.92
|20<sup>a</sup><br />43<sup>b</sup>
|34<sup>a</sup><br />74<sup>b</sup>
|5.0<sup>a</sup><br />2.3<sup>b</sup>
|170<sup>a</sup><br />310 - 330<sup>b</sup>
|16
|110<sup>a</sup><br />130<sup>b</sup>
|ca. 500
|1070 - 1080
|}
</figtable>
<sup>a</sup>solution annealed, and cold rolled<br />
<sup>b</sup>solution annealed, cold rolled, and precipitation hardened<br />
<figtable id="tab:Mechanical Properties of Other Precipitation Hardening Copper Alloys">
<caption>'''<!--Table 5.20:-->Mechanical Properties of Other Precipitation Hardening Copper Alloys'''</caption>
<table class="twocolortable">
<tr><th><p class="s16">Material</p></th><th><p class="s16">Hardness</p><p class="s16">Condi- tion</p></th><th><p class="s16">Tensile</p><p class="s16">Strength R<span class="s18">m</span></p><p class="s16">[MPa]</p></th><th><p class="s16">0,2% Yield</p><p class="s16">Strength R<span class="s18">p02</span></p><p class="s16">[MPa]</p></th><th><p class="s16">Elongation</p><p class="s16">A50</p><p class="s16">[%]</p></th><th><p class="s16">Vickers</p><p class="s16">Hardness</p><p class="s16">HV</p></th><th><p class="s16">Spring Bending</p><p class="s16">Limit <span class="s19">F</span><span class="s18">FB </span>[MPa]</p></th></tr><tr><td><p class="s16">CuCr</p></td><td><p class="s16">R 230<span class="s18">a</span></p><p class="s16">R 400<span class="s18">a </span>R 450<span class="s18">b </span>R 550<span class="s18">b</span></p></td><td><p class="s33">><span class="s16"> 230</span></p><p class="s33">><span class="s16"> 400</span></p><p class="s33">><span class="s16"> 450</span></p><p class="s33">><span class="s16"> 550</span></p></td><td><p class="s33">><span class="s16"> 80</span></p><p class="s33">><span class="s16"> 295</span></p><p class="s33">><span class="s16"> 325</span></p><p class="s33">><span class="s16"> 440</span></p></td><td><p class="s16">30</p><p class="s16">10</p><p class="s16">10</p><p class="s16">8</p></td><td><p class="s33">><span class="s16"> 55</span></p><p class="s33">><span class="s16"> 120</span></p><p class="s33">><span class="s16"> 130</span></p><p class="s33">><span class="s16"> 150</span></p></td><td><p class="s16">350</p></td></tr><tr><td><p class="s16">CuZr</p></td><td><p class="s16">R 260<span class="s18">a</span></p><p class="s16">R 370<span class="s18">a </span>R 400<span class="s18">b </span>R 420<span class="s18">b</span></p></td><td><p class="s33">><span class="s16"> 260</span></p><p class="s33">><span class="s16"> 370</span></p><p class="s33">><span class="s16"> 400</span></p><p class="s33">><span class="s16"> 420</span></p></td><td><p class="s33">><span class="s16"> 100</span></p><p class="s33">><span class="s16"> 270</span></p><p class="s33">><span class="s16"> 280</span></p><p class="s33">><span class="s16"> 400</span></p></td><td><p class="s16">35</p><p class="s16">12</p><p class="s16">12</p><p class="s16">10</p></td><td><p class="s33">><span class="s16"> 55</span></p><p class="s33">><span class="s16"> 100</span></p><p class="s33">><span class="s16"> 105</span></p><p class="s33">><span class="s16"> 115</span></p></td><td><p class="s16">280</p></td></tr><tr><td><p class="s16">CuCr1Zr</p></td><td><p class="s16">R 200<span class="s18">a</span></p><p class="s16">R 400<span class="s18">b</span></p><p class="s16">R 450<span class="s18">b</span></p></td><td><p class="s33">><span class="s16"> 200</span></p><p class="s33">><span class="s16"> 400</span></p><p class="s33">><span class="s16"> 450</span></p></td><td><p class="s33">><span class="s16"> 60</span></p><p class="s33">><span class="s16"> 210</span></p><p class="s33">><span class="s16"> 360</span></p></td><td><p class="s16">30</p><p class="s16">12</p><p class="s16">10</p></td><td><p class="s33">><span class="s16"> 70</span></p><p class="s33">><span class="s16"> 140</span></p><p class="s33">><span class="s16"> 155</span></p></td><td><p class="s16">420</p></td></tr></table>
</figtable>
=====<!--5.1.6.2.2-->Copper-Zirconium Alloys=====
The solubility of Zirconium in copper is 0.15 wt% Zr at the eutectic temperature of 980°C <xr id="fig:Copper corner of the copper zirconium for up to 0.5-wt zirconium"/><!--(Fig. 5.36)-->. Copper-zirconium materials have a similar properties spectrum compared to the one for copper-chromium materials. At room temperature the mechanical properties of copper-zirconium are less suitable than those of copper chromium, its temperature stability is however at least the same.
=====<!--5.1.6.2.3-->Copper-Chromium-Zirconium Alloys=====
The earlier used CuCr and CuZr materials have been partially replaced over the years by the capitation hardening three materials alloy CuCr1Zr. This material exhibits high mechanical strength at elevated temperatures and good oxidation resistance as well as high softening temperatures. In its hardened condition CuCr1Zr has also a high electrical conductivity <xr id="fig:Softening of CuCr1Zr after 1hr annealing"/><!--(Bild 5.37)-->. Their usage extends from mechanically and thermally highly stressed parts such as contact tulips in high voltage switchgear to electrodes for resistance welding.
<xr id="fig:Copper corner of the copper zirconium for up to 0.5-wt zirconium"/><!--Fig. 5.36:--> Copper corner of the copper- zirconium for up to 0.5 wt% zirconium
<xr id="fig:Softening of CuCr1Zr after 1hr annealing"/><!--Fig. 5.37:--> Softening of CuCr1Zr after 1 hr annealing and after 90% cold working
<div class="multiple-images">
<figure id="fig:Copper corner of the copper zirconium for up to 0.5-wt zirconium">
[[File:Copper corner of the copper zirconium for up to 0.5-wt zirconium.jpg|right|thumb|Copper corner of the copper- zirconium for up to 0.5 wt% zirconium]]
</figure>
<figure id="fig:Softening of CuCr1Zr after 1hr annealing">
[[File:Softening of CuCr1Zr after 1hr annealing.jpg|right|thumb|Softening of CuCr1Zr after 1 hr annealing and after 90% cold working]]
</figure>
</div>
<div class="clear"></div>
==Referenzen==
[[Trägerwerkstoffe#Referenzen|Referenzen]]
[[en:Precipitation_Hardening_Copper_Alloys]]