| W-Cu-Ni composites are widely used as electrical contact materials because of their excellent properties.However,W and Cu are immiscible with each other,which limits the application of W-Cu matrix composites.In this paper,Zr and Ti alloy element were used to prepare W-Cu-Ni/Y2O3 composite powders by high energy ball milling,and new W-Cu matrix composite materials were prepared by Spark plasma sintering.The effects of Zr,Ti doping ratio and content on the microstructure and properties of W-Cu-Ni/Y2O3 composites were studied.The main results are as follows(1)The results show that the sintering properties of W-Cu-Ni/Y2O3 composite powder can be improved by doping Zr and Ti.The actual density of the sample prepared by adding 1.5wt.%Ti+1.5wt.%Zr is 16.2435 g/cm3,the relative density is greater than 99.5%,and the grain size is about 2?m.Zr and Ti doping elements exist different forms in the composites.Ti is more compatible with Ni,and Ti Ni intermetallic compound is formed between W grains.However,most Zr elements combine with Cu to form CuZr intermetallic compounds.(2)The microhardness and tensile strength of the composites can be improved by increasing the amount of Zr and Ti doping.However,due to the different content of Ti and Zr elements in the materials,the enhancement efficiency is also different.The results show that when Ti content is more than 1.5wt.%,the material still maintains high tensile strength at 600?.When the content of Zr element is increased to 3.5wt.%,the tensile strength also increases,but at 600?,due to the metal sweating effect,the loss of CuZr phase will cause the tensile strength to decrease rapidly.(3)Increasing the doping amount of Zr Ti can improve the conductivity of the composite,but increasing the doping ratio of Ti can reduce the conductivity of the composite.The mass loss of W-Cu-Ni/Y2O3 composites can be significantly reduced by doping Ti and Zr.The mass loss of the samples with 3.5wt.%Zr+0.5wt.%Ti is 75.81%less than that of the samples without doping. |
PDF Full Text Request