Study On Microstructure And Properties Of W-Cu Refractory Alloy By Oscillating Pressuresintering

W-Cu refractory alloy has the properties of high heat resistance,high conductivity,anti-arc and anti-friction,etc.It is often used in military electromagnetic rail gun,High-Voltage Contact material,electronic packaging material and aviation gyro rotor material.W-Cu refractory alloy has a wide range of applications.Due to the defects and technical limitations of sintering,the commonly used sintering techniques and processes are not beneficial for the further optimization of microstructure and properties of W-Cu refractory alloy.Therefore,it is of great practical significance to develop a new sintering technique to obtain high density,fine grain and uniform microstructure W-Cu refractory gold at low temperature.In this paper,the 90W-10 Cu alloy was firstly prepared by mixing and dispersing the high-purity W powder and Cu powder with high-energy ball mill,and the particle size of the powder is below 4?m.Secondly,by comparing the Hot-pressed sintering process with the oscillating pressure sintering process,the relationships between the grain growth activation energy,sintering process,microstructure and properties of W-Cu refractory alloy were studied.Finally,the mechanism of oscillating pressure sintering was analyzed.The influence factors of oscillating pressure sintering process include sintering temperature,sintering time,median pressure,amplitude and frequency,etc.W-Cu refractory alloy was prepared at different sintering temperatures.When the oscillation pressure was at 30±5MPa,the frequency was 1Hz,and the sintering temperature was at1080? for 1h,we found that the sample density,hardness and conductivity were99.38%,163.8HV and 12.9%IACS,respectively.Prepared under different sintering time of W-Cu refractory alloy,oscillation pressure sintering process on the oscillation of 30±5Mpa,the frequency of 1Hz,the sintering temperature was 1100? for 2h,the sample density,hardness,electrical conductivity were 99.25%,148.3HV,14.5%IACS,respectively.Under the oscillating pressure sintering process of grain size was abnormal grain grew up but lower than 4 microns.When the pressure was 30 MPa,the sintering temperature was 1400? for 1h,the density,hardness and conductivity of the samples were 99.40%,193.5HV and 25.9%IACS,respectively.The grain size of the samples exceeded 9?m.The results show that compared with hot pressing sintering,oscillating pressure sintering can effectively promote the densification of W-Cu refractory alloy,reduce thesintering temperature and the activation energy of grain growth in the sintering process.Besides,such technology can inhibit the grain growth,improve the material properties,and facilitate the obtaining of high-density.More importantly,we can synthetic fine-grained W-Cu refractory alloy at low temperature.