Copper Alloys C
ast copper alloys are known for their versatility. Tey are used in plumbing fixtures, ship propellers, power plant water impellers and bushing
and bearing sleeves because they are easily cast, have a long history of suc- cessful use, are readily available from a multitude of sources, can achieve a range of physical and mechanical properties and are easily machined, brazed, soldered, polished or plated.
Properties Following is a list of physical
and mechanical properties common to cast copper alloys. Although not every property is applicable to every alloy, the range isn’t found in any other alloy group: • Good corrosion resistance, which contributes to durability and long- term cost-effectiveness;
• Mechanical properties ranging from pure copper, which is soft and ductile, to manganese-bronze, which ap- proaches the mechanical properties of quenched and tempered steel. Almost all copper alloys retain their me- chanical properties, including impact toughness, at low temperatures;
• Termal and electrical conductivity greater than any metal except silver. Te conductivity of copper drops when alloyed, but it still conducts heat and electricity better than other corrosion-resistant materials;
• Bio-fouling resistance, as copper inhibits marine organism growth. Although this property (unique to copper) decreases upon alloying, it is retained at a useful level in many alloys, such as copper-nickel;
• Low friction and wear rates, such as with the high-leaded tin-bronzes, which are cast into sleeve bearings and exhibit lower wear rates than steel;
• Good castability. All copper alloys can be sand cast, and many can be centrifugal, continuous, permanent mold and die cast;
• Good machinability. Leaded copper alloys are free-cutting at high ma- chining speeds, and many unleaded alloys, such as nickel-aluminum bronze, are readily machinable at recommended feeds and speeds with proper tooling;
• Ease of post-casting processing, as good surface finish and high tolerance control can be achieved.
2014 CASTING SOURCE DIRECTORY
The 131-ton propeller (top) for the Emma Maersk was cast in bronze for its strength and wear resistance.
METAL CASTING DESIGN & PURCHASING 33
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164 |
Page 165 |
Page 166 |
Page 167 |
Page 168 |
Page 169 |
Page 170 |
Page 171 |
Page 172