Effect of Ti on the Structure and Properties of Cu-15Ni-10Mn Alloy As-Cast Smelted at Atmosphere

Cu-15Ni-10Mn alloy as-cast, which smelted at atmosphere, has a typical dendrite structure in Ni segregation characteristics. The content of Ni is higher on dendrite arms spacing than on the dendrite arms, but the content of Mn is less than on the trunk. Due to the Mn oxides easily, the processing performance of alloy as-cast can't meet the requirement of metalworking. The gas content of ingots can be reduced by adding a small amount of zinc during smelting, and the metalworking features can be improved by adding trace Ti that will refine the arms of alloy. The research results show that the grains of Cu-15Ni-10Mn alloy as-cast can be refined by tiny amount of Ti. The grain size decreases with the increase of the content of Ti, the branches size of alloy adding 0.2% Ti is about 30 mu m that is only 49.4% the size of the alloy without Ti. Titanium, copper and Nickel can form compounds of CuNi2Ti. The hardness peak of alloy with 0.2%Co is 114Hv that is 8% higher than the alloy without Ti. The electrical conductivity of Cu-15Ni-10Mn alloy as-cast waves not clearly.