Changes

====5Besides the naturally hard copper materials, precipitation hardening copper alloys play also an important role as carrier materials for electrical contacts.1By means of a suitable heat treatment, finely dispersed precipitations of a second phase can be achieved, that increases the mechanical strength of these copper alloys significantly.6.1 Copper-Beryllium Alloys (Beryllium Bronze)====

The cause for precipitation hardening of CuBe materials is the rapidly diminishing solubility of beryllium in copper as temperature decrease. As thephase diagram for CuBe shows, 2.4 wt% of Be are soluble in Cu at 780°C ====<xr id="fig:Phase diagram of copperberyllium with temperature ranges for brazing and annealing treatments"/> (Fig. !--5.28)1. In this temperature range annealed CuBe alloys are homogeneous(solution annealing)6. The homogeneous state can be frozen through rapid cooling to room temperature 1-->Copper-Beryllium Alloys (quenchingBeryllium Bronze). Through a subsequent annealing at 325°C the desired precipitation hardening is achieved which results in a significant increase in mechanical strength and electrical conductivity of CuBe ''(Table 5.17)''. The final strength and hardness values depend on the annealing temperature and time as well as on the initial degree of cold working ''(Table 5.18)'' and [[#figures7|(Figs. 43 – 75)]](Figs. 5.29 - 5.31).====

The cause for precipitation hardening of CuBe materials, is the rapidly diminishing solubility of beryllium in copper as temperature decreases. As thephase diagram for CuBe shows, 2.4 wt% of Be are soluble in Cu at 780°C (<figure xr id="fig:Phase diagram of copperberyllium with temperature ranges for brazing and annealing treatmentsPhase_diagram_of_copperberyllium_with_temperature_ranges_for_brazing_and_annealing_treatments"/><!--(Fig. 5.28: Phase diagram of copperberyllium with )-->). In this temperature ranges for brazing and range, annealed CuBe alloys are homogeneous(solution annealing treatments[[File:Phase diagram of copper beryllium with ). The homogeneous state can be frozen through rapid cooling to room temperature ranges(quenching).jpg|right|thumb|Phase diagram of copper- beryllium with temperature ranges for brazing and Through a subsequent annealing treatments]]</figure> As at 325°C, the desired precipitation hardening alloys CuBe materials, mainly CuBe2 and CuBe1.7 have gained broad usage as current carrying contact springs because of their outstanding mechanical properties. Besides these CuCo2Be and CuNi2Beis achieved, which have medium results in a significant increase in mechanical strength and a relatively high electricalconductivity, are also used as contact carrier materialsof CuBe (<xr id="tab:Physical_Properties_of_Selected_Copper_Beryllium_Alloys"/><!--(Tab. After stamping and forming into desired contact configurations these CuBe materials are then precipitation hardened5. CuBe alloys are available as semi17)--finished materials in a variety of cold work conditions>). They can also be supplied The final strength and used in hardness values depend on the already precipitation hardened condition without significant strength losses. In this case the hardening was already performed at the alloy producer. Since Beryllium is rated annealing temperature and time, as well as a carcinogen by on the European regulation EUinitial degree of cold working (<xr id="tab:Mechanical Properties of Selected Copper-67Beryllium Alloys"/548, it has been tried to reach the application properties of the well established CuBe1><!--(Table 5.7 18)--> and CuBe2 alloys with a lower Be content. The development efforts for alternate precipitation hardening materials without toxic and declaration requiring additive materials<xr id="fig:Precipitation_hardening_of_CuBe2_at_325°C_after_different_cold_working"/>, for example CuNiCoSi<xr id="fig:Precipitation_hardening_of_CuBe2_(soft)_at_325°C"/>, are aimed at the replacement of CuBe. <div xr id="figures7fig:Precipitation_hardening_of_CuBe2_(half hard)_at_different_annealing_temperatures"/>).

<xr id="fig:Precipitation As precipitation hardening alloys CuBe materials, mainly CuBe2 and CuBe1.7 have gained broad usage as current carrying contact springs because of their outstanding mechanical properties. Besides these, CuCo2Be and CuNi2Be, which have medium mechanical strength and a relatively high electricalconductivity, are also used as contact carrier materials. After stamping and forming into desired contact configurations, these CuBe materials are then precipitation hardened. CuBe alloys are available as semi-finished materials in a variety of CuBe2 at 325°C after different cold working"/> Figwork conditions. 5They can also be supplied and used in the already precipitation hardened condition, without significant strength losses.29: Precipitation In this case, the hardening of CuBe2 was already performed at 325°C after different cold workingthe alloy producer.

<xr id="fig:Precipitation hardening Since Beryllium is rated as a carcinogen by the European regulation EU-67/548, it has been tried to reach the application properties of the well established CuBe1.7 and CuBe2 (soft) at 325°C"/> Figalloys with a lower Be content. 5Development efforts for alternative precipitation hardening materials without toxic and declarable additives are underway, e.30: Precipitation hardening of CuBe2 (soft) at 325°C <xr id="fig:Precipitation hardening of CuBe2 (half hard) at different annealing temperatures"/> Figg. 5CuNiCoSi as a substitute for CuBe.31: Precipitation hardening of CuBe2 (half hard) at different annealing temperatures</div>

<figure id="fig:Phase diagram of copperberyllium with temperature ranges for brazing and annealing treatmentsPhase_diagram_of_copperberyllium_with_temperature_ranges_for_brazing_and_annealing_treatments">[[File:Phase diagram of copper beryllium with temperature ranges.jpg|rightleft|thumb|<caption>Phase diagram of copper- beryllium with temperature ranges for brazing and annealing treatments</caption>]]

<figure id="fig:Precipitation hardening of CuBe2 at 325°C after different cold workingPrecipitation_hardening_of_CuBe2_at_325°C_after_different_cold_working"> [[File:Precipitation hardening of CuBe2 at 325C.jpg|rightleft|thumb|<caption>Precipitation hardening of CuBe2 at 325°C after different cold working</caption>]]

<figure id="fig:Precipitation hardening of CuBe2 Precipitation_hardening_of_CuBe2_(soft) at 325°C_at_325°C"> [[File:Precipitation hardening of CuBe2 (soft) at 325C.jpg|rightleft|thumb|<caption>Precipitation hardening of CuBe2 (soft) at 325°C</caption>]]

<figure id="fig:Precipitation hardening of CuBe2 Precipitation_hardening_of_CuBe2_(half hard) at different annealing temperatures_at_different_annealing_temperatures"> [[File:Precipitation hardening of CuBe2 half hard.jpg|rightleft|thumb|<caption>Precipitation hardening of CuBe2 (half hard) at different annealing temperatures</caption>]]

<figtable id="tab:Physical_Properties_of_Selected_Copper_Beryllium_Alloys"><caption>'''<!--Table 5.1817: Mechanical -->Physical Properties of Selected Copper-Beryllium Alloys''' (2 Teile!)</caption>

{| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material<br />Designation<br />EN UNS !Composition<br />[wt%]!Density<br />[g/cm³]!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^-6/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[[#text-reference1|^a]]<br />12 - 13[[#text-reference2|^b]]<br />11[[#text-reference3|^c]]|14 - 16<br />21 - 22<br />19|11 - 12.5[[#text-reference1|^a]]<br />7.7 - 8.3[[#text-reference2|^b]]9.1[[#text-reference3|^c]]|110|17|125[[#text-reference1|^a]]<br />[[#text-reference2|^b]]|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[[#text-reference1|^a]]<br />12 - 13[[#text-reference2|^b]]<br />11[[#text-reference3|^c]]|14 - 16<br />21 - 22<br />19|11 - 12.5[[#text-reference1|^a]]<br />7.7 - 8.3[[#text-reference2|^b]]<br />9.1[[#text-reference3|^c]]|110|17|125[[#text-reference1|^a]]<br />135[[#text-reference2|^b]]|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[[#text-reference1|^a]]<br />25 - 27[[#text-reference2|^b]]<br />27 - 34[[#text-reference3|^c]]|19 - 24<br />43 - 47<br />47 - 59|7.1- 9.1[[#text-reference1|^a]]<br />3.7 - 4.0[[#text-reference2|^b]]<br />2.9[[#text-reference3|^c]]|210|18|131[[#text-reference1|^a]]<br />138[[#text-reference2|^b]]|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[[#text-reference1|^a]]<br />25 - 27[[#text-reference2|^b]]<br />27 - 34[[#text-reference3|^c]]|19 - 24<br />43 - 47<br />47 - 59|7.1 - 9.1[[#text-reference1|^a]]<br />3.7 - 4.0[[#text-reference2|^b]]<br />2 Other Precipitation Hardening Copper Alloys=.9[[#text-reference3|^c]]|230|18|131[[#text-reference1|^a]]<br />138[[#text-reference2|^b]]|ca. 480|1060 - 1100|}<div id="text-reference1">_a solution annealed, and cold rolled</div><div id="text-reference2">_b solution annealed, cold rolled, and precipitation hardened</div><div id="text-reference3">_c solution annealed, cold rolled, and precipitation hardened at mill (mill hardened)</div></figtable><br/><br/>

<figtable id====="tab:Mechanical Properties of Selected Copper-Beryllium Alloys"><caption>'''<!--Table 5.1.6.2.1 18:-->Mechanical Properties of Selected Copper-Chromium Beryllium Alloys====='''</caption>

As the phase diagram shows{| class="twocolortable" style="text-align: left; font-size: 12px"|-!Material!Hardness<br />Condition!Tensile Strength R_m<br />[MPa]!0, copper2% Yield Strength<br />R_p02<br />[MPa]!Elongation<br />A₅₀<br />[%]!Vickers<br />Hardness<br />HV!Bend Radius[[#text-chromium has a similar hardening profile compared reference4|¹]]<br />perpendicular to CuBe <xr id="fig:Copper corner of the copperbr />rolling direction!Bend Radius[[#text-chromium phase diagram for up reference4|¹]]<br />parallel to <br />rolling direction!Spring Bending<br />Limit σ_FB<br />[MPa]!Spring Fatigue<br />Limit σ_BW<br />[MPa]|-|CuBe1,7|R 390[[#text-reference5|^a]]<br />R 680[[#text-reference5|^a]]<br />R 1030[[#text-reference6|^b]]<br />R 1240[[#text-reference6|^b]]<br />R 680[[#text-reference7|^c]]<br />R 1100[[#text-reference7|^c]]|380 -520<br />680 - 820<br />1030 - 1240<br />1240 - 1380<br />680 - 750<br />1100 - 1200|&ge; 180<br />&ge; 600<br />&ge; 900<br />&ge; 1070<br />&ge; 480<br />&ge; 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|0.8 wt% chromium"x t<br />3 x t<br />(Fig1. 5.32). In the hardened stage CuCr has limitations to work hardening. Compared to copper it has 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[[#text-reference5|^{a better temperature stability with good electrical conductivity. Hardness and electrical conductivity as}]]<br />R 690[[#text-reference5|^{a function of cold working and precipitation hardening conditions are illustrated in}]]<br />R 1140[[#text-reference6|^b]]<br />R 1310[[#text-reference6|^b]]<br />R 690[[#text-reference7|^c]]<br />R 1200[[#figures8text-reference7|(Figs. 6 – 9)^c]] Figs|410 -540<br />690 - 820<br />1140 - 1310<br />1310 - 1480<br />690 - 760<br />1200 - 1320|&ge; 190<br />&ge; 650<br />&ge; 1000<br />&ge; 1150<br />&ge; 480<br />&ge; 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. 5.33x 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[[#text-reference5|^a]]<br />R 550[[#text-reference5|^a]]<br />R 650[[#text-reference6|^b]]<br />R 850[[#text-reference6|^b]]<br />R 520[[#text-reference7|^c]]|250 - 380<br />550 - 700<br />650 - 820<br />850 - 1000<br />520 -620|&ge; 140<br />&ge; 450<br />&ge; 520<br />&ge; 750<br />&ge; 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 />3.35, 5 x t<br />1 x t| <br /> <br />360<br />650<br />300| <br /> <br />220<br />250<br />210|}<xr div id="tabtext-reference4">₁ t:tab5Strip thickness max. 0.195 mm</div><div id="text-reference5">_a solution annealed, and cold rolled</div><div id="text-reference6">_b (Tables 5.19) solution annealed, cold rolled, and precipitation hardened</div><xr div id="tab:tab5.20text-reference7">_c solution annealed, cold rolled, and precipitation hardened at mill (Tab. 5.20mill hardened).</div></figtable> <br/><br/>

Copper====<!--chromium materials are especially suitable for use as electrodes for resistance welding5.1. During brazing the loss in hardness is limited if low melting brazing alloys and reasonably short heating times are used6.2-->Other Precipitation Hardening Copper Alloys====

=====<figure id="fig:Copper corner of the copper!--chromium phase diagram for up to 05.1.8 wt% chromium">Fig6. 52.32: Copper corner of the copper1--chromium phase diagram for up to 0.8 wt% chromium[[File:>Copper corner of the copper chromium phase diagram.jpg|right|thumb|Copper corner of the copper-chromium phase diagram for up to 0.8 wt% chromium]] </figure>Chromium Alloys=====

As the phase diagram shows, copper-chromium has a similar hardening profile compared to CuBe (<div xr id="figures5fig: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-->and <xr id="figtab:Softening Physical Properties of precipitation hardened Other Precipitation Hardening Copper Alloys"/><!--(Tables 5.19)--> and subsequently cold worked CuCr1<xr id="tab:Mechanical Properties of Other Precipitation Hardening Copper Alloys"/> Fig<!--(Tab. 5.33: Softening of precipitation20)--hardened and subsequently cold worked CuCr1 after 4hrs annealing>).

<xr id="fig:Electrical conductivity of precipitation hardened CuCr 0.6"/> Fig. 5Copper-chromium materials are especially suitable for use as electrodes for resistance welding.34 a: Electrical conductivity of precipitation hardened CuCr 0During brazing the loss in hardness is limited, if low melting brazing alloys and reasonably short heating times are used.6 as a function of annealing conditions

<xr iddiv class="fig:Hardness of precipitation hardened CuCr 0.6multiple-images"/> Fig. 5.34 b: Hardness of precipitation hardened CuCr 0.6 as a function of annealing conditions

<xr figure id="fig:Electrical conductivity and hardness Copper corner of precipitation hardened CuCr the copper-chromium phase diagram for up to 0.68 wt% chromium"/> Fig[[File:Copper corner of the copper chromium phase diagram. 5.35: Electrical conductivity and hardness jpg|left|thumb|<caption>Copper corner of precipitation hardened CuCr the copper-chromium phase diagram for up to 0.6 after cold working8 wt% chromium</caption>]] </divfigure>

[[File:Softening of precipitation hardened and subsequently cold worked CuCr1.jpg|rightleft|thumb|<caption>Softening of precipitation-hardened and subsequently cold worked CuCr1 after 4hrs annealing</caption>]]

[[File:Electrical conductivity of precipitation hardened CuCr 0.6.jpg|rightleft|thumb|<caption>Electrical conductivity of precipitation hardened CuCr 0.6 as a function of annealing conditions</caption>]]

[[File:Hardness of precipitation hardened CuCr 0.6.jpg|rightleft|thumb|<caption>Hardness of precipitation hardened CuCr 0.6 as a function of annealing conditions</caption>]]

[[File:Electrical conductivity and hardness of precipitation hardened CuCr 0.6.jpg|rightleft|thumb|<caption>Electrical conductivity and hardness of precipitation hardened CuCr 0.6 after cold working</caption>]]

<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/cm³]!colspan="2" style="text-align:center"|Electrical<br />Conductivity !Electrical<br />Resistivity<br />[μΩ·cm]!Thermal<br />Conductivity<br />[W/(2 Teilem·K)]!Coeff. of Linear<br />Thermal<br />Expansion<br />[10^-6/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[[#text-reference8|^a]]<br />48[[#text-reference9|^b]]|45[[#text-reference8|^a]]<br />83[[#text-reference9|^b]]|3.8[[#text-reference8|^a]]<br />2.1[[#text-reference9|^b]]|170[[#text-reference8|^a]]<br />315[[#text-reference9|^b]]|17|112|ca. 450|980 - 1080|-|CuZr|Zr 0.1 - 0.3<br />Cu Rest|8.9|35[[#text-reference8|^a]]<br />52[[#text-reference9|^b]]|60[[#text-reference8|^a]]<br />90[[#text-reference9|^b]]|2.9[[#text-reference8|^a]]<br />1.9[[#text-reference9|^b]]|340[[#text-reference8|^a]]|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[[#text-reference8|^a]]<br />43[[#text-reference9|^b]]|34[[#text-reference8|^a]]<br />74[[#text-reference9|^b]]|5.0[[#text-reference8|^a]]<br />2.3[[#text-reference9|^b]]|170[[#text-reference8|^a]]<br />310 - 330[[#text-reference9|^b]]|16|110[[#text-reference8|^a]]<br />130[[#text-reference9|^b]]|ca. 500|1070 - 1080|}<div id="text-reference8">_a solution annealed, and cold rolled</div><div id="text-reference9">_b solution annealed, cold rolled, and precipitation hardened</div></figtable><br /><br />

<figtable id="tab:tab5.20Mechanical Properties of Other Precipitation Hardening Copper Alloys"><caption>'''<!--Table 5.20: -->Mechanical Properties of Other Precipitation Hardening Copper Alloys'''</caption>

<table borderclass="1" cellspacing="0" style="border-collapse:collapsetwocolortable"><tr><tdth><p class="s16">Material</p></tdth><tdth><p class="s16">Hardness</p><p class="s16">Condi- tion</p></tdth><tdth><p class="s16">Tensile</p><p class="s16">Strength R<span class="s18">m</span></p><p class="s16">[MPa]</p></tdth><tdth><p class="s16">0,2% Yield</p><p class="s16">Strength R<span class="s18">p02</span></p><p class="s16">[MPa]</p></tdth><tdth><p class="s16">Elongation</p><p class="s16">A50</p><p class="s16">[%]</p></tdth><tdth><p class="s16">Vickers</p><p class="s16">Hardness</p><p class="s16">HV</p></tdth><tdth><p class="s16">Spring Bending</p><p class="s16">Limit <span class="s19">F</span><span class="s18">FB </span>[MPa]</p></tdth></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">&gt;<span class="s16"> 230</span></p><p class="s33">&gt;<span class="s16"> 400</span></p><p class="s33">&gt;<span class="s16"> 450</span></p><p class="s33">&gt;<span class="s16"> 550</span></p></td><td><p class="s33">&gt;<span class="s16"> 80</span></p><p class="s33">&gt;<span class="s16"> 295</span></p><p class="s33">&gt;<span class="s16"> 325</span></p><p class="s33">&gt;<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">&gt;<span class="s16"> 55</span></p><p class="s33">&gt;<span class="s16"> 120</span></p><p class="s33">&gt;<span class="s16"> 130</span></p><p class="s33">&gt;<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">&gt;<span class="s16"> 260</span></p><p class="s33">&gt;<span class="s16"> 370</span></p><p class="s33">&gt;<span class="s16"> 400</span></p><p class="s33">&gt;<span class="s16"> 420</span></p></td><td><p class="s33">&gt;<span class="s16"> 100</span></p><p class="s33">&gt;<span class="s16"> 270</span></p><p class="s33">&gt;<span class="s16"> 280</span></p><p class="s33">&gt;<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">&gt;<span class="s16"> 55</span></p><p class="s33">&gt;<span class="s16"> 100</span></p><p class="s33">&gt;<span class="s16"> 105</span></p><p class="s33">&gt;<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">&gt;<span class="s16"> 200</span></p><p class="s33">&gt;<span class="s16"> 400</span></p><p class="s33">&gt;<span class="s16"> 450</span></p></td><td><p class="s33">&gt;<span class="s16"> 60</span></p><p class="s33">&gt;<span class="s16"> 210</span></p><p class="s33">&gt;<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">&gt;<span class="s16"> 70</span></p><p class="s33">&gt;<span class="s16"> 140</span></p><p class="s33">&gt;<span class="s16"> 155</span></p></td><td><p class="s16">420</p></td></tr></table>

=====<!--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 solubility of Zirconium in copper is 0earlier used CuCr and CuZr materials have been partially replaced over the years, by the capitation hardening three materials alloy CuCr1Zr.15 wt% Zr This material exhibits high mechanical strength at the eutectic temperature of 980°C 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:Copper corner Softening of the copper zirconium for up to 0.5-wt zirconiumCuCr1Zr after 1hr annealing"/> <!--(Fig. Bild 5.3637). 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 chromiumTheir usage extends from mechanically and thermally highly stressed parts, its temperature stability is however at least the samesuch as contact tulips in high voltage switchgear or electrodes for resistance welding.

[[File:Copper corner of the copper zirconium for up to 0.5-wt zirconium.jpg|right|thumb|Figure 10: Copper corner of the copper- zirconium for up to 0.5 wt% zirconium]]

[[File:Softening of CuCr1Zr after 1hr annealing.jpg|right|thumb|Figure 11: Softening of CuCr1Zr after 1 hr annealing and after 90% cold working]]