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→Other Precipitation Hardening Copper Alloys
The cause for precipitation hardening of CuBe materials, is the rapidly diminishing solubility of beryllium in copper as temperature decreases. As the
phase 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)-->). In this temperature range, annealed CuBe alloys are homogeneous(solution annealing). The homogeneous state can be frozen through rapid cooling to room temperature (quenching). 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 (<xr id="tab:Physical_Properties_of_Selected_Copper_Beryllium_Alloys"/><!--(Tab. 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 (<xr id="tab:Mechanical Properties of Selected Copper-Beryllium Alloys"/><!--(Table 5.18)--> and <xr id="fig:Precipitation_hardening_of_CuBe2_at_325°C_after_different_cold_working"/>, <xr id="fig:Precipitation_hardening_of_CuBe2_(soft)_at_325°C"/>, <xr id="fig:Precipitation_hardening_of_CuBe2_(half hard)_at_different_annealing_temperatures"/>).
<div class="multiple-images">
<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|left|thumb|<caption>Phase diagram of copper- beryllium with temperature ranges for brazing and annealing treatments</caption>]]
</figure>
<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|left|thumb|<caption>Precipitation hardening of CuBe2 at 325°C after different cold working</caption>]]
</figure>
<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|left|thumb|<caption>Precipitation hardening of CuBe2 (soft) at 325°C</caption>]]
</figure>
<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|left|thumb|<caption>Precipitation hardening of CuBe2 (half hard) at different annealing temperatures</caption>]]
</figure>
<figtable id="tab:tab5.17Physical_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"
!Composition<br />[wt%]
!Density<br />[g/cm<sup>3</sup>]
!colspan="2" style="text-align:center"|Electrical<br />Conductivity<br />[MS/m] [% IACS]
!Electrical<br />Resistivity<br />[μΩ·cm]
!Thermal<br />Conductivity<br />[W/(m·K)]
!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|<sup>a</sup>]]<br />12 - 13[[#text-reference2|<sup>b</sup>]]<br />11[[#text-reference3|<sup>c</sup>]]
|14 - 16<br />21 - 22<br />19
|11 - 12.5[[#text-reference1|<sup>a</sup>]]<br />7.7 - 8.3[[#text-reference2|<sup>b</sup><br />]]9.1[[#text-reference3|<sup>c</sup>]]
|110
|17
|125[[#text-reference1|<sup>a</sup>]]<br />135[[#text-reference2|<sup>b</sup>]]
|ca. 380
|890 - 1000
|Be 1.8 - 2.1<br />Co 0.3<br />Ni 0.3<br />Cu Rest
|8.3
|8 - 9[[#text-reference1|<sup>a</sup>]]<br />12 - 13[[#text-reference2|<sup>b</sup>]]<br />11[[#text-reference3|<sup>c</sup>]]
|14 - 16<br />21 - 22<br />19
|11 - 12.5[[#text-reference1|<sup>a</sup>]]<br />7.7 - 8.3[[#text-reference2|<sup>b</sup>]]<br />9.1[[#text-reference3|<sup>c</sup>]]
|110
|17
|125[[#text-reference1|<sup>a</sup>]]<br />135[[#text-reference2|<sup>b</sup>]]
|ca. 380
|870 - 980
|Co 2.0 - 2.8<br />Be 0.4 - 0.7<br />Ni 0.3<br />Cu Rest
|8.8
|11 - 14[[#text-reference1|<sup>a</sup>]]<br />25 - 27[[#text-reference2|<sup>b</sup>]]<br />27 - 34[[#text-reference3|<sup>c</sup>]]
|19 - 24<br />43 - 47<br />47 - 59
|7.1 - 9.1[[#text-reference1|<sup>a</sup>]]<br />3.7 - 4.0[[#text-reference2|<sup>b</sup>]]<br />2.9[[#text-reference3|<sup>c</sup>]]
|210
|18
|131[[#text-reference1|<sup>a</sup>]]<br />138[[#text-reference2|<sup>b</sup>]]
|ca. 450
|1030 - 1070
|Ni 1.4 - 2.2<br />Be 0.2 - 0.6<br />Co 0.3<br />Cu Rest
|8.8
|11 - 14[[#text-reference1|<sup>a</sup>]]<br />25 - 27[[#text-reference2|<sup>b</sup>]]<br />27 - 34[[#text-reference3|<sup>c</sup>]]
|19 - 24<br />43 - 47<br />47 - 59
|7.1 - 9.1[[#text-reference1|<sup>a</sup>]]<br />3.7 - 4.0[[#text-reference2|<sup>b</sup>]]<br />2.9[[#text-reference3|<sup>c</sup>]]
|230
|18
|131[[#text-reference1|<sup>a</sup>]]<br />138[[#text-reference2|<sup>b</sup>]]
|ca. 480
|1060 - 1100
|}
<div id="text-reference1"><sub>a</sub> solution annealed, and cold rolled</div>
<div id="text-reference2"><sub>b</sub> solution annealed, cold rolled, and precipitation hardened</div>
<div id="text-reference3"><sub>c</sub> solution annealed, cold rolled, and precipitation hardened at mill (mill hardened)</div>
</figtable>
<br/>
<br/>
{| class="twocolortable" style="text-align: left; font-size: 12px"
!Elongation<br />A<sub>50</sub><br />[%]
!Vickers<br />Hardness<br />HV
!Bend Radius[[#text-reference4|<sup>1)</sup>]]<br />perpendicular to<br />rolling direction!Bend Radius[[#text-reference4|<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[[#text-reference5|<sup>a</sup>]]<br />R 680[[#text-reference5|<sup>a</sup>]]<br />R 1030[[#text-reference6|<sup>b</sup>]]<br />R 1240[[#text-reference6|<sup>b</sup>]]<br />R 680[[#text-reference7|<sup>c</sup>]]<br />R 1100[[#text-reference7|<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
|-
|CuBe2
|R 410[[#text-reference5|<sup>a</sup>]]<br />R 690[[#text-reference5|<sup>a</sup>]]<br />R 1140[[#text-reference6|<sup>b</sup>]]<br />R 1310[[#text-reference6|<sup>b</sup>]]<br />R 690[[#text-reference7|<sup>c</sup>]]<br />R 1200[[#text-reference7|<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
|-
|CuCo2Be<br />CuNi2Be
|R 250[[#text-reference5|<sup>a</sup>]]<br />R 550[[#text-reference5|<sup>a</sup>]]<br />R 650[[#text-reference6|<sup>b</sup>]]<br />R 850[[#text-reference6|<sup>b</sup>]]<br />R 520[[#text-reference7|<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
| <br /> <br />220<br />250<br />210
|}
</figtablediv id="text-reference4"><supsub>1)</supsub> t: Strip thickness max. 0.5 mm<br /div><supdiv id="text-reference5"><sub>a</supsub>solution annealed, and cold rolled<br /div> <supdiv id="text-reference6"><sub>b</supsub>solution annealed, cold rolled, and precipitation hardened<br /div> <supdiv id="text-reference7"><sub>c</supsub>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"/div>(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:tab5.19"/figtable> (Tables 5.19) and <xr id="tab:tab5.20"br/> (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"br/> 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!--5.1. 56.33: Softening of precipitation2--hardened and subsequently cold worked CuCr1 after 4hrs annealing>Other Precipitation Hardening Copper Alloys====
=====<xr id="fig:Electrical conductivity of precipitation hardened CuCr 0!--5.1.6"/> Fig. 52.34 a: Electrical conductivity of precipitation hardened CuCr 0.6 as a function of annealing conditions1-->Copper-Chromium Alloys=====
As the phase diagram shows, copper-chromium has a similar hardening profile compared to CuBe (<xr id="fig:Hardness Copper corner of precipitation hardened CuCr the copper-chromium phase diagram for up to 0.68 wt% chromium"/> <!--(Fig. 5.34 b: Hardness of precipitation 32)-->). In the hardened stage CuCr 0has limitations to work hardening. Compared to copper it has a better temperature stability with good electrical conductivity.6 Hardness and electrical conductivity as a function of annealing cold working and precipitation hardening conditionsare illustrated in [[#figures8|(Figs. 6 – 9]]<!--Figs. 5.33-5.35--> and <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)-->).
<div class="multiple-images">
<figtable id="tab:tab5.19Physical 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"
!Composition<br />[wt%]
!Density<br />[g/cm<sup>3</sup>]
!colspan="2" style="text-align:center"|Electrical<br />Conductivity<br />[MS/m] [% IACS]
!Electrical<br />Resistivity<br />[μΩ·cm]
!Thermal<br />Conductivity<br />[W/(m·K)]
!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|<sup>a</sup>]]<br />48[[#text-reference9|<sup>b</sup>]]|45[[#text-reference8|<sup>a</sup>]]<br />83[[#text-reference9|<sup>b</sup>]]|3.8[[#text-reference8|<sup>a</sup>]]<br />2.1[[#text-reference9|<sup>b</sup>]]|170[[#text-reference8|<sup>a</sup>]]<br />315[[#text-reference9|<sup>b</sup>]]
|17
|112
|Zr 0.1 - 0.3<br />Cu Rest
|8.9
|35[[#text-reference8|<sup>a</sup>]]<br />52[[#text-reference9|<sup>b</sup>]]|60[[#text-reference8|<sup>a</sup>]]<br />90[[#text-reference9|<sup>b</sup>]]|2.9[[#text-reference8|<sup>a</sup>]]<br />1.9[[#text-reference9|<sup>b</sup>]]|340[[#text-reference8|<sup>a</sup>]]
|16
|135
|Cr 0.5 - 1.2<br />Zr 0.03 - 0.3<br />Cu Rest
|8.92
|20[[#text-reference8|<sup>a</sup>]]<br />43[[#text-reference9|<sup>b</sup>]]|34[[#text-reference8|<sup>a</sup>]]<br />74[[#text-reference9|<sup>b</sup>]]|5.0[[#text-reference8|<sup>a</sup>]]<br />2.3[[#text-reference9|<sup>b</sup>]]|170[[#text-reference8|<sup>a</sup>]]<br />310 - 330[[#text-reference9|<sup>b</sup>]]
|16
|110[[#text-reference8|<sup>a</sup>]]<br />130[[#text-reference9|<sup>b</sup>]]
|ca. 500
|1070 - 1080
|}
<div id="text-reference8"><sub>a</sub> solution annealed, and cold rolled</div>
<div id="text-reference9"><sub>b</sub> solution annealed, cold rolled, and precipitation hardened</div>
</figtable>
<br />
<br />
<table class="twocolortable">
</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 or electrodes for resistance welding.
<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|Figure 10: 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|Figure 11: Softening of CuCr1Zr after 1 hr annealing and after 90% cold working]]
</figure>
</div>
<div class="clear"></div>
==References==
[[Contact Carrier Materials#References|References]]
[[de:Aushärtbare_Kupfer-Legierungen]]