Alloys like brasses (CuZn), tin bronzes (CuSN), and German silver (CuNiZn), for which the required hardness is achieved by cold working , are defined as naturally hard alloys. Included in this group are also the silver bronzes (CuAg) with 2 – 6 wt% of Ag.
====<!--5.1.4.1 -->Copper-Zinc Alloys Test (Brasses)====
Copper-zinc alloys are widely used as contact carrier materials in switching devices for electrical power engineering because of their high electrical conductivity, the higher mechanical strength combined with good formability compared to pure copper ''(Tables <xr id="tab:Physical_Properties_of_ Selected_Copper_Zinc_Alloys"/><!--(Tab. 5.7 )--> and <xr id="tab:Mechanical_Properties_of_Selected_Copper_Zinc_Alloys"/><!--(Tab. 5.8)''-->), and at the same time their reasonable economic costs. Especially suitable are the brasses with up to 37 wt% Zn content which are according to the phase diagram all made up from the " α -phase of the CuZn system ''(<xr id="fig:Phase_diagram_of_copper_zinc_for_the_range_of_0_60_wt_zinc"/><!--(Fig. 5.5)''-->). It is important to note the strong dependence of the electrical conductivity and mechanical strength on the zinc content ''(<xr id="fig:Mechanical_properties_of_brass_ depending_on_the_copper_content_after_cold_working_of_0_and_50"/><!--(Fig. 5.6)''-->).
<figtable id="tab:Physical_Properties_of_ Selected_Copper_Zinc_Alloys"><caption>'''<!--Table 5.7:-->Physical Properties of Selected Copper-Zinc 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]!!!!!!|-|CuZn5<br />CW500L<br />C21000|Cu 94 - 96<br />Zn Rest|8.87|33|57|3.8|243|18.0|127||1055 - 1065|-|CuZn10<br />CW501L<br />C22000|Cu 89 - 91<br />Zn Rest|8.79|25|43|4.0|184|18.2|125||1030 - 1045|-|CuZn15<br />CW502L<br />C23000|Cu 84 - 86<br />Zn Rest|8.75|21|36|4.8|159|18.5|122|ca. 250|1005 - 1025|-|CuZn20<br />CW503L<br />C24000|Cu 79 - 81<br />Zn Rest|8.67|19|33|5.3|142|18.8|120|ca. 240|980 - 1000|-|CuZn30<br />CW505L<br />C26000|Cu 69 - 71<br />Zn Rest|8.53|16|28|6.3|124|19.8|114|ca. 230|910 - 940|-|CuZn37<br />CW508L<br />C27200|Cu 62 - 64<br />Zn Rest|8.45|15.5|27|6.5|121|20.2|110|ca. 220|900 - 920|-|CuZn23Al3Co<br />CW703R<br />C68800|Cu 73.5<br />Al 3.4<br />Co 0.4<br />Zn Rest|8.23|9.8|17|10.2|78|18.2|116|ca. 280|950 - 1000|}</figtable> <figtable id="tab:Mechanical_Properties_of_Selected_Copper_Zinc_Alloys"><caption>'''<!--Table 5.8:-->Mechanical Properties of Selected Copper-Zinc 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% YieldStrength<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]|-|CuZn5|R 230<br />R 270<br />R 340|230 - 280<br />270 -350<br />340 - 440|≤ 130<br />≥ 200<br />≥ 280|36<br />12<br />4|45 - 90<br />70 - 120<br />110 - 160|0 x t<br />0 x t<br />|0 x t<br />0 x t<br />|250|130|-|CuZn10|R 240<br />R 280<br />R 350|240 - 290<br />280 - 360<br />350 - 450|≤ 140<br />≥ 200<br />≥ 290|36<br />13<br />4|50 - 100<br />80 - 130<br />110 - 160|0 x t<br />0 x t<br />|0 x t<br />0 x t<br />|260|140|-|CuZn15|R 300<br />R 350<br />R 410<br />R 480<br />R 550|300 - 370<br />350 - 420<br />410 - 490<br />480 - 560<br />≥ 550|≤ 150<br />≥ 270<br />≥ 360<br />≥ 420<br />≥ 480|16<br />8<br />3<br />1<br />|85 - 120<br />100 - 150<br />125 - 155<br />150 - 180<br />≥ 170|0 x t<br />0 x t<br />0 x t<br />1 x t<br />|0 x t<br />0 x t<br />1 x t<br />3 x t<br />|300|160|-|CuZn20|R 270<br />R 320<br />R 400<br />R 480|270 - 320<br />320 - 400<br />400 - 480<br />480 - 570|≤ 150<br />≥ 200<br />≥ 320<br />≥ 440|38<br />20<br />5<br />3|55 - 105<br />95 - 155<br />120 - 180<br />≥ 150|0 x t<br />0 x t<br />0 x t<br />|0 x t<br />0 x t<br />0 x t<br />|320|180|-|CuZn30|R 270<br />R 350<br />R 410<br />R 480|270 - 350<br />350 - 430<br />410 - 490<br />480 - 580|≤ 160<br />≥ 200<br />≥ 430<br />≥ 430|40<br />21<br />9<br />4|95 - 125<br />120 - 155<br />150 - 180<br />170 - 200|0 x t<br />0 x t<br />0 x t<br />1 x t|0 x t<br />1 x t<br />2 x t<br />3 x t|330|180|-|CuZn37|R 300<br />R 350<br />R 410<br />R 480<br />R 550|300 - 370<br />350 - 440<br />410 - 490<br />480 - 560<br />550 - 640|≤ 180<br />≥ 200<br />≥ 260<br />≥ 430<br />≥ 500|38<br />19<br />8<br />3<br />|55 - 105<br />95 - 155<br />120 - 190<br />≥ 150<br />≥ 170|0 x t<br />0 x t<br />0 x t<br />0.5 x t<br />1 x t|0 x t<br />0 x t<br />0 x t<br />1 x t<br />3 x t|350|190|-|CuZn23Al3Co|R 660<br />R 740<br />R 820|660 - 750<br />740 - 830<br />≥ 820|≥ 580<br />≥ 660<br />≥ 780|10<br />3<br />2|190 - 220<br />210 - 240<br />≥ 235|0 x t<br />1 x t<br />|0 x t<br />2 x t<br />|≥ 400|230|}</figtable><sup>1)</sup> t: Strip thickness max. 0.5 mm The main disadvantages of these alloys are with increasing zinc content , the also increasing tendency towards tension crack corrosion and the poorer stress relaxation properties , compared to other copper alloys.
One of the special brass alloys used as a contact carrier material is CuSn23Al3Co. This material exhibits significantly higher mechanical strength
than the standard brass alloys. Even so , this material is a naturally hardening alloy, a suitable heat treatment allows to further increase its strength.
Fig. 5.5: Phase diagram of copper<div class="multiple-zinc for the range of 0-60 wt% zinc[[File:Phase diagram of copper zinc.jpg|right|thumb|Phase diagram of copper-zinc for the range of 0-60 wt% zinc]]images">
Fig. 5.6<figure id="fig: Mechanical properties of brass depending on the copper content (after cold working of 0 and 50%)Phase_diagram_of_copper_zinc_for_the_range_of_0_60_wt_zinc">[[File:Mechanical properties Phase diagram of brass depending on the copper contentzinc.jpg|rightleft|thumb|Mechanical properties <caption>Phase diagram of brass depending on copper-zinc for the copper content (after cold working range of 0 and 50-60 wt%)zinc</caption>]]</figure>
Fig. 5<figure id="fig:Mechanical_properties_of_brass_ depending_on_the_copper_content_after_cold_working_of_0_and_50">[[File:Mechanical properties of brass depending on the copper content.7: Strain hardening jpg|left|thumb|<caption>Mechanical properties of CuZn36 by brass depending on the copper content (after cold formingworking of 0 and 50%)</caption>]]</figure>
Fig<figure id="fig:Strain hardening of CuZn36 by cold forming">[[File:Strain hardening of CuZn36 by cold forming. 5.8: Softening jpg|left|thumb|<caption>Strain hardening of CuZn36 after 3 hrs annealing after 25% by cold workingforming</caption>]]</figure>
<figure id====5.1.4"fig:Softening of CuZn36 after 3 hrs annealing after 25% cold working">[[File:Softening of CuZn36 25.2 Copper-Tin Alloys (Tin Bronze)===jpg|left|thumb|<caption>Softening of CuZn36 after 3 hrs annealing after 25% cold working</caption>]]</figure></div><div class="clear"></div>
Because of their good elastic spring properties and formability the copper====<!-tin alloys CuSn6 and CuSn8 are standard materials for spring contact elements in electrome-chanical components such as connectors, switches, and relays ''(Tables 5.9 and 51.10)''4. Besides these other alloys such as CuSn4 and CuSn5 and the multi2-->Copper-metal tin bronze CuSn3Zn9 have significant usage – mainly in North America.Figure 5.10 shows the copper rich side of the phase diagram for the CuSn system. The mechanical property values achieved by cold forming are superior to these of the brass alloys ''Tin Alloys (Fig. 5.11Tin Bronze)''. They increase significantly with increasing Sn content. The work hardening and softeningbehavior are shown for the example of CuSn8 in Figures 5.12 and 5.13. The stress relaxation properties for CuSn alloys are good for up to 100°C, deteriorate however quickly for temperatures above 150°C.====
Because of their good elastic spring properties and formability, the copper-tin alloys CuSn6 and CuSn8 are standard materials for spring contact elements in electromechanical components, such as connectors, switches and relays (<xr id="tab:Physical Properties of Copper-Tin Alloys"/><!--(Tab. 5.9)--> and <xr id="tab:Mechanical Properties of Copper-Tin Alloys"/><!--(Tab.5.10)-->). Besides these, other alloys such as CuSn4, CuSn5 and the multi-metal tin bronze CuSn3Zn9 have significant usage – mainly in North America. <!--5.10--><xr id="fig:Phase diagram of the Cu-Sn system for the range of 0 – 30 wt% Sn"/> shows the copper rich side of the phase diagram for the CuSn system. The mechanical property values achieved by cold forming are superior to these of the brass alloys (<xr id="fig:Mechanical properties of tin bronze depending on the tin content (cold working 0 and 50%)"/><!--(Fig. 5.911)-->). They increase significantly with increasing Sn content. The work hardening and softening behavior are shown for the example of CuSn8 in <xr id="fig:Strain hardening of CuSn8 by cold working"/><!--Figures 5.12--> and <xr id="fig: Softening of CuZn36 CuSn8 after 3 hrs annealing after 50% cold working"/><!--Fig. 5.13-->. The stress relaxation properties for CuSn alloys are good for up to 100°C, deteriorate however quickly for temperatures above 150°C.
Fig. 5.10: Phase diagram of the Cu-Sn system for the range of 0 – 30 wt% Sn.
<figtable id="tab:Physical Properties of Copper-Tin Alloys"><caption>'''<!--Table 5.79: -->Physical Properties of Selected Copper-Zinc Tin Alloys (2 teile!)'''</caption>
Table {| 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]!!!!!!|-|CuSn4<br />CW450K<br />C51100|Sn 3.5 - 4.5<br />P 0.01 - 0.4<br />Cu Rest|8.85|12.0|20|8.3|118|18.0|120|ca. 260|960 - 1060|-|CuSn5<br />CW451K<br />C51000|Sn 4.5 - 5.5<br />P 0.01 - 0.4<br />Cu Rest|8: Mechanical Properties of Selected Copper.85|10.0|17|10.0|96|18.0|120|ca. 260|940 - 1050|-|CuSn6<br />CW452K<br />C51900|Sn 5.5 - 7.0<br />P 0.01 - 0.4<br />Cu Rest|8.80|9.0|15|11.1|75|18.5|118|ca. 280|910 - 1040|-|CuSn8<br />CW453K<br />C52100|Sn 7.5 - 8.5<br />P 0.01 - 0.4<br />Cu Rest|8.80|7.5|13|13.3|67|18.5|115|ca. 320|875 - 1025|-|CuSn3Zn9<br />CW454K<br />C42500|Zn 7.5 - 10<br />Sn 1.5 -Zinc Alloys (3.5<br />P 0.2<br />Ni 0.2<br />Cu Rest|8.75|12|28|6.2 teile!)|120|18.4|126|ca. 250|900 - 1015|}</figtable>
Table 5.9: Physical Properties of Copper-Tin Alloys (2 teile!)
Table 5.10: Mechanical Properties of Copper-Tin Alloys (2 teile!)
Fig. <figtable id="tab:Mechanical Properties of Copper-Tin Alloys"><caption>'''<!--Table 5.1110: -->Mechanical properties Properties of tin bronze depending on the tin content (cold working 0 and 50%)Copper-Tin Alloys'''</caption>
Fig{| 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]|-|CuSn4|R 290<br />R 390<br />R 480<br />R 540<br />R 610|290 - 390<br />390 - 490<br />480 - 570<br />540 - 630<br />≥ 610|≤ 190<br />≥ 210<br />≥ 420<br />≥ 490<br />≥ 540|40<br />13<br />5<br />4<br />2|70 - 100<br />115 - 155<br />150 - 180<br />170 - 200<br />≥ 190|0 x t<br />0 x t<br />0 x t<br />0 x t|0 x t<br />0 x t<br />0 x t<br />1 x t|420|200|-|CuSn5|R 310<br />R 400<br />R 490<br />R 550<br />R 630<br />R 690|310 - 390<br />400 - 500<br />490 - 580<br />550 - 640<br />630 - 720<br />≥ 690|≤ 250<br />≥ 240<br />≥ 430<br />≥ 510<br />≥ 600<br />≥ 670|45<br />17<br />10<br />6<br />3|75 - 105<br />120 - 160<br />160 - 190<br />180 - 210<br />200 - 230<br />≥ 220|0 x t<br />0 x t<br />0 x t<br />0 x t<br />1 x t|0 x t<br />0 x t<br />0 x t<br />1 x t<br />2 x t|460|220|-|CuSn6|R 350<br />R 420<br />R 500<br />R 560<br />R 640<br />R 720|350 - 420<br />420 - 520<br />500 - 590<br />560 - 650<br />640 - 730<br />≥ 720|≤ 300<br />≥ 260<br />≥ 450<br />≥ 500<br />≥ 600<br />≥ 690|45<br />20<br />10<br />7<br />4|80 - 110<br />125 - 165<br />160 - 190<br />180 - 210<br />200 - 230<br />≥ 220|0 x t<br />0 x t<br />0 x t<br />0 x t<br />1 x t|0 x t<br />0 x t<br />0 x t<br />1 x t<br />2 x t|480|230|-|CuSn8|R 370<br />R 450<br />R 540<br />R 600<br />R 660<br />R 740|370 - 450<br />450 - 550<br />540 - 630<br />600 - 690<br />660 - 750<br />≥ 740|≤ 300<br />≥ 280<br />≥ 460<br />≥ 530<br />≥ 620<br />≥ 700|50<br />23<br />15<br />7<br />4|90 - 120<br />135 - 175<br />170 - 200<br />190 - 220<br />210 - 240<br />≥ 230|0 x t<br />0 x t<br />0 x t<br />1 x t<br />2 x t|0 x t<br />0 x t<br />0 x t<br />1 x t<br />2 x t|520|240|-|CuSn3Zn9|R 320<br />R 380<br />R 430<br />R 510<br />R 580<br />R 660|320 - 380<br />380 - 430<br />430 - 520<br />510 - 600<br />580 - 690<br />≥ 660|≤ 230<br />≥ 200<br />≥ 330<br />≥ 430<br />≥ 520<br />≥ 610|25<br />18<br />6<br />3<br />4|80 - 110<br />110 - 140<br />140 - 170<br />160 - 190<br />180 - 210<br />≥ 200|0 x t<br />0 x t<br />0 x t<br />0 x t<br />1 x t|0 x t<br />0 x t<br />0 x t<br />1 x t<br />2 x t|500|210|}</figtable><sup>1)</sup> t: Strip thickness max. 0. 5.12: Strain hardening of CuSn8 by cold workingmm
Fig. 5.13: Softening of CuSn8 after 3 hrs annealing after 50% cold working<div class="multiple-images">
<figure id====5.1.4"fig:Softening of CuZn36 50">[[File:Softening of CuZn36 50.jpg|left|thumb|<caption>Softening of CuZn36 after 3 Copper-Nickel-Zinc Alloys (German Silver)====hrs annealing after 50% cold working</caption>]]</figure>
<figure id="fig:Phase diagram of the Cu-Sn system for the range of 0 – 30 wt% Sn">[[File:Phase diagram of the Cu Sn system.jpg|left|thumb|<caption>Phase diagram of the Cu-Sn system for the range of 0 – 30 wt% Sn</caption>]]</figure> <figure id="fig:Mechanical properties of tin bronze depending on the tin content (cold working 0 and 50%)">[[File:Mechanical properties of tin bronze depending on the tin content.jpg|left|thumb|<caption>Mechanical properties of tin bronze depending on the tin content (cold working 0 and 50%)</caption>]]</figure> <figure id="fig:Strain hardening of CuSn8 by cold working">[[File:Strain hardening of CuSn8 by cold working.jpg|left|thumb|<caption>Strain hardening of CuSn8 by cold working</caption>]]</figure> <figure id="fig:Softening of CuSn8 after 3 hrs annealing after 50% cold working">[[File:Softening of CuSn8 50.jpg|left|thumb|<caption>Softening of CuSn8 after 3 hrs annealing after 50% cold working</caption>]]</figure></div><div class="clear"></div> ====<!--5.1.4.3-->Copper-Nickel-Zinc Alloys (German Silver)==== Despite its lower electrical conductivity, the good spring properties, high corrosion resistance, and the good workability make copper-nickel-zinc alloys a frequently used spring contact carrier in switches and relays. As illustrated in the phase diagram , the most commonly used materials are in the " α -range which means that they are single-phase alloys ''(<xr id="fig:Copper rich region of the ternary copper-nickel-zinc phase diagram with indication of the more commonly available german silver materials"/><!--(Fig. 5.14)''-->). The formability and strength properties of german silver are comparable to those of the copper-tin alloys. The work hardening and softening behavior is illustrated on the example of CuNi12Zn24 in <xr id="fig:Strain hardening of CuNi12Zn24 by cold working"/><!--Figures 5.15 --> and <xr id="fig:Softening of CuNi12Zn24 after 3 hrs annealing after 50% cold working"/><!--5.16-->.
The relaxation behavior of Cu-Ni-Zn alloys is superior to the one for the tin bronzes. Additional advantages are the very good weldability, brazing
properties, and the high corrosion resistance of these copper-nickel-zinc alloys.
Fig<figtable id="tab:tab5. 11"><caption>'''<!--Table 5.1411: -->Physical Properties of Copper rich region of the ternary copper-nickelNickel-zinc phase diagram with indication of the more commonly available german silver materialsZinc Alloys'''</caption>
Table 5.11{| class="twocolortable" style="text-align: Physical Properties of Copperleft; font-Nickelsize: 12px"|-Zinc Alloys !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/(2 teilem·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]!!!!!!|-|CuNi12Zn24<br />CW403J<br />C75700|Cu 63- 66<br />Ni 11 - 13<br />Mn 0.5<br />Fe 0.3<br />Zn Rest|8.67|4.4|7|30|42|18|125|ca. 400|1020 - 1065|-|CuNi18Zn20<br />CW409J<br />C76400|Cu 60 - 63<br />Ni 17 - 19<br />Mn 0.5<br />Fe 0.3<br />Zn Rest|8.73|3.3|5|23|33|17.7|135|ca. 440|1055 - 1105|-|CuNi18Zn27<br />CW410J<br />C77000|Cu 53 - 56<br />Ni 17 - 19<br />Mn 0.5<br />Fe 0.3<br />Zn Rest|8.70|3.3|5|23|32|17.7|135|ca. 440|1050 - 1100|}</figtable>
Table 5.12: Mechanical Properties of Copper-Nickel-Zinc Alloys (2 teile!)
Fig. 5.15: Strain hardening of CuNi12Zn24 by cold working
Fig<figtable id="tab:tab5. 12"><caption>'''<!--Table 5.1612: Softening -->Mechanical Properties of CuNi12Zn24 after 3 hrs annealing after 50% cold workingCopper-Nickel-Zinc 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]|-|CuNi12Zn24|R 360<br />R 430<br />R 490<br />R 550<br />R ≥ 610|360 - 430<br />430 - 510<br />490 - 580<br />550 - 640<br />≥ 580|≤ 230<br />≥ 230<br />≥ 400<br />≥ 480<br />≥ 580|35<br />8<br />6<br />3<br />2|80 - 110<br />110 - 150<br />150 - 180<br />170 - 200<br />≥ 190|0 x t<br />0 x t<br />0 x t<br />0 x t|0 x t<br />0 x t<br />0 x t<br />0 x t|480|210|-|CuNi18Zn20|R 380<br />R 450<br />R 500<br />R 580<br />R ≥ 640|380 - 450<br />450 - 520<br />500 - 590<br />580 - 670<br />≥ 640|≤ 250<br />≥ 250<br />≥ 410<br />≥ 510<br />≥ 600|27<br />9<br />5<br />2|85 - 115<br />115 - 160<br />160 - 190<br />180 - 210<br />≥ 220|0 x t<br />0 x t<br />0 x t<br />0 x t|0 x t<br />0 x t<br />0 x t<br />0 x t|520|220|-|CuNi18Zn27|R 390<br />R 470<br />R 540<br />R 600<br />R ≥ 700|390 - 470<br />470 - 540<br />540 - 630<br />600 - 700<br />≥ 700|≤ 280<br />≥ 280<br />≥ 450<br />≥ 550<br />≥ 680|30<br />11<br />5.<br />2|90 - 120<br />120 - 170<br />170 - 200<br />190 - 220<br />≥ 220|0 x t<br />0 x t<br />0 x t<br />0 x t|0 x t<br />0 x t<br />0 x t<br />1 x t|550|250|}</figtable><sup>1)</sup> t: Strip thickness max.40.4 Copper-Silver-(Cadmium) Alloys (Silver Bronze)====5 mm
Besides the low<div class="multiple-allowed CuAg0.1 other copper materials with higher silver contents (2-6 wt%) are also used as contacts carrier materials. Some of them contain additionally 1.5 wt% Cd. The phase diagram ''(Fig. 5.17)'' shows that in principle the CuAg alloys can be precipitation hardened, but the possible increase in mechanical strength is rather small.images">
<figure id="fig:Copperrich region of the ternary copper-nickel-zinc phase diagram with indication of the more commonly available german silver alloys have good spring properties and compared to other spring materials have a high electrical conductivity ''(Tables 5">[[File:Copper rich region of the termary copper nickel zinc phase diagram.13 and 5.14)''. The mechanical strength values in the strongly worked condition are comparable to those jpg|right|thumb|Figure 10: Copper rich region of the ternary copper-tin alloys. Work hardening and softening behavior are shown for the example nickel-zinc phase diagram with indication of CuAg2 ''(Figs. 5.18 – 5.20)''. For the relaxation behavior the more commonly available german silver bronzes are superior to German silver and tin bronze.materials]]</figure>
Because <figure id="fig:Strain hardening of their good spring properties combined with high electrical conductivity silver bronzes are suitable for the use contact springs in relaysCuNi12Zn24 by cold working">under higher current loads[[File:Strain hardening of CuNi 12Zn24 by cold working. Taking advantage jpg|left|thumb|<caption>Strain hardening of their high temperature stability they are also used as current carrying contacts in high voltage switchgear and as electrode material for resistance welding.CuNi12Zn24 by cold working</caption>]]</figure>
Fig. 5.17<figure id="fig:Softening of CuNi12Zn24 after 3 hrs annealing after 50% cold working">[[File: Phase diagram Softening of copper-silver for the range CuNi12Zn24 50.jpg|left|thumb|<caption>Softening of 0 – 40 wtCuNi12Zn24 after 3 hrs annealing after 50% silvercold working</caption>]]</figure></div><div class="clear"></div>
Table ====<!--5.13: Physical Properties of Selected 1.4.4-->Copper-Silver-(Cadmium) Alloys (2 teile!Silver Bronze)====
Table Besides the low-allowed CuAg0.1, other copper materials with higher silver contents (2-6 wt%) are also used as contacts carrier materials. Some of them contain additional 1.5wt% Cd.14The phase diagram <xr id="fig: Mechanical Properties Phase diagram of copper-silver for the range of Selected Copper0 – 40 wt% silver"/><!-Silver-(Cadmium) Alloys (2 teile!Fig. 5.17)--> shows that in principle the CuAg alloys can be precipitation hardened, but the possible increase in mechanical strength is rather small.
FigCopper-silver alloys have good spring properties and compared to other spring materials have a high electrical conductivity (<xr id="tab:tab5.13"/><!--(Tab. 5.1813)--> and <xr id="tab: Strain tab5.14"/><!--(Tab. 5.14)-->). The mechanical strength values in the strongly worked condition are comparable to those of the copper-tin alloys. Work hardening and softening behavior are shown for the example of CuAg2 by cold working[[#figures5|(Figs. 13 – 15)]]<!--(Figs. 5.18 – 5.20)-->. For the relaxation behavior, the silver bronzes are superior to German silver and tin bronze.
FigBecause of their good spring properties combined with high electrical conductivity, silver bronzes are suitable for the use contact springs in relaysunder higher current loads. 5Taking advantage of their high temperature stability, they are also used as current carrying contacts in high voltage switchgear and as electrode material for resistance welding.19: Softening of CuAg2 after 1 hr annealing after 40% cold working
Fig <figtable id="tab:tab5. 13"><caption>'''<!--Table 5.2013: -->Physical Properties of Selected Copper-Silver-(Cadmium) 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]!!!!!!|-|CuAg2<br />not standardized<br />|Ag 2<br />Cu Rest<br />|9.0|49|85|2.0|330|17.5|123|ca. 330|1050 - 1075|-|CuAg2Cd1,5<br />not standardized<br />|Ag 2<br />Cd1,5<br />Cu Rest|9.0|43|74|2.3|260|17.8|121|ca. 350|970 - 1055|-|CuAg6<br />not standardized<br />|Ag 6<br />Cu Rest|9.2|38|66|2.4|270|17.5|120||960 - 1050|}</figtable> <figtable id="tab:tab5.14"><caption>'''<!--Table 5.14:-->Mechanical Properties of Selected Copper-Silver-(Cadmium) 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]|-|CuAg2|R 280<br />R 380<br />R 450<br />R 550|280 - 380<br />380 - 460<br />450 - 570<br />≥ 550|≤ 180<br />≥ 300<br />≥ 420<br />≥ 500|30<br />6<br />3<br />1|50 - 110<br />100 - 140<br />130 - 165<br />≥ 160|0 x t<br />0 x t<br />1 x t|0 x t<br />0 x t<br />1 x t|400|190|-|CuAg2Cd1,5|R 300<br />R 380<br />R 480<br />R 600|300 - 380<br />380 - 490<br />480 - 620<br />≥ 600|≤ 190<br />≥ 310<br />≥ 440<br />≥ 550|30<br />8<br />3<br />1|55 - 110<br />100 - 145<br />130 - 170<br />≥ 160|0 x t<br />0 x t<br />1 x t|0 x t<br />0 x t<br />1 x t|440|220|-|CuAg6|R 320<br />R 400<br />R 500<br />R 650|320 - 400<br />400 - 510<br />500 - 660<br />≥ 650|≤ 210<br />≥ 330<br />≥ 460<br />≥ 610|30<br />6<br />3<br />1|70 - 120<br />110 - 150<br />145 - 175<br />≥ 175|0 x t<br />0 x t<br />1 x t|0 x t<br />0 x t<br />1 x t|460|230|}</figtable><sup>1)</sup> t: Strip thickness max. 0.5 mm <div class="multiple-images"> <figure id="fig:Phase diagram of copper-silver for the range of 0 – 40 wt% silver">[[File:Phase diagram of copper silver.jpg|left|thumb|<caption>Phase diagram of copper-silver for the range of 0 – 40 wt% silver</caption>]]</figure> <figure id="fig:Strain hardening of CuAg2 by cold working">[[File:Strain hardening of CuAg2 by cold working.jpg|left|thumb|<caption>Strain hardening of CuAg2 by cold working</caption>]]</figure> <figure id="fig:Softening of CuAg2 after 1 hr annealing after 40% cold working">[[File:Softening of CuAg2 40.jpg|left|thumb|<caption>Softening of CuAg2 after 1 hr annealing after 40% cold working</caption>]]</figure> <figure id="fig:Softening of CuAg2 after 1 hr annealing after 80% cold working">[[File:Softening of CuAg2 80.jpg|left|thumb|<caption>Softening of CuAg2 after 1 hr annealing after 80% cold working</caption>]]</figure></div><div class="clear"></div>
==References==
[[Contact Carrier Materials#References|References]]
[[de:Naturharte_Kupfer-Legierungen]]
