#Copper-Nickel Alloys
cupro-nickel alloys have considerable strength, resistance to corrosion and erosion The 8020 or 7030 cupro-nickels are used for condenser tubes as they strongly resist the attack of and sea waters. Monel metal is a well-known alloy composed of estuarine approximately two-thirds nickel with the remainder being principally copper. It is used for turbine blades, pump rods and impellers, scavenge valves and superheated steam valves. Monel metal retains its high strength at high temperatures. With the addition of 2-4% aluminium, forming a material known as K monel, it can be temper-hardened thus its strength can be increased still further without detracting from its other properties.
#White metals
White metal-bearing alloys may be either tin or lead-based materials containing antimony and copper orantimonyalone.Tin-basedwhite metals are sometimes referred to as Babbitt metals after Sir Isaac Babbitt who patented them originally. These metals are the most commonly used of the white metals because of (1) their good bearing surface and (2) uniform microstructure.
The use of copper in a white metal ensures uniform distribution of the hard cuboids of the inter-metallic compound of antim and tin within soft, tin-rich matrik. Coefficient of friction for the 0002. a white metal bearing when lubricated is approximately The melting point of white metal varies with composition but is approximately between 200C and 300C (see Table 1.5).