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→Copper-Silver-(Cadmium) Alloys (Silver Bronze)
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 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. <div class="multiple-images"> <figure id="fig:Phase_diagram_of_copper_zinc_for_the_range_of_0_60_wt_zinc">[[File:Phase diagram of copper zinc.jpg|left|thumb|<caption>Phase diagram of copper-zinc for the range of 0-60 wt% zinc</caption>]]</figure> <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.jpg|left|thumb|<caption>Mechanical properties of brass depending on the copper content (after cold working of 0 and 50%)</caption>]]</figure> <figure id="fig:Strain hardening of CuZn36 by cold forming">[[File:Strain hardening of CuZn36 by cold forming.jpg|left|thumb|<caption>Strain hardening of CuZn36 by cold forming</caption>]]</figure> <figure id="fig:Softening of CuZn36 after 3 hrs annealing after 25% cold working">[[File:Softening of CuZn36 25.jpg|left|thumb|<caption>Softening of CuZn36 after 3 hrs annealing after 25% cold working</caption>]]</figure></div><div class="clear"></div>
{| 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|8.85|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 - 3.5<br />P 0.2 Copper<br />Ni 0.2<br />Cu Rest|8.75|12|28|6.2|120|18.4|126|ca. 250|900 -Tin Alloys (Tin Bronze)====1015|}</figtable>
=====<!--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. <figtable id="tab:tab5.11"><caption>'''<!--Table 5.11:-->Physical Properties of Copper-Nickel-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]!!!!!!|-|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> <figtable id="tab:tab5.12"><caption>'''<!--Table 5.12:-->Mechanical Properties of Copper-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. 0.5 mm <div class="multiple-images"> <figure id="fig:Copper rich region of the ternary copper-nickel-zinc phase diagram with indication of the more commonly available german silver materials">[[File:Copper rich region of the termary copper nickel zinc phase diagram.jpg|right|thumb|Figure 10: Copper rich region of the ternary copper-nickel-zinc phase diagram with indication of the more commonly available german silver materials]]</figure> <figure id="fig:Strain hardening of CuNi12Zn24 by cold working">[[File:Strain hardening of CuNi 12Zn24 by cold working.jpg|left|thumb|<caption>Strain hardening of CuNi12Zn24 by cold working</caption>]]</figure> <figure id="fig:Softening of CuNi12Zn24 after 3 hrs annealing after 50% cold working">[[File:Softening of CuNi12Zn24 50.jpg|left|thumb|<caption>Softening of CuNi12Zn24 after 3 hrs annealing after 50% cold working</caption>]]</figure></div><div class="clear"></div> ====<!--5.1.4.4-->Copper-Silver-(Cadmium) Alloys (Silver Bronze)====
<figtable id="tab:tab5.13">
<caption>'''<!--Table 5.13:-->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.1350|970 - 1055|-|CuAg6<br />not standardized<br />|Ag 6<br />Cu Rest|9.2|38|66|2.4|270|17.4 Copper-Silver5|120||960 -(Cadmium) Alloys (Silver Bronze)=====1050|}</figtable>
==References==
[[Contact Carrier Materials#References|References]]
[[de:Naturharte_Kupfer-Legierungen]]