Preparation Of Diamond / Copper-boron Alloy Composites Via Gas Pressure Infiltration And Properties Study

As the main preparation method of diamond/copper composites,the diamond/copper composites prepared by gas pressure infiltration have high densification and excellent thermal conductivity.The process parameters can significantly affect the thermophysical properties of the composites,which is the research focus of mass production of high-quality diamond/copper composites.In this paper,diamond and Cu-B（0.5 wt.%）were compounded by gas pressure infiltration method,and the effects of infiltration pressure and diamond particle size on the interface structure,thermophysical properties and mechanical properties of the composites were studied.The main contents and conclusions are as follows:（1）When the diamond particle size is 550μm,diamond/copper-boron alloy composites were prepared under the gas pressure of 6 MPa and 10MPa respectively.The result shows that under the gas pressure of 10 MPa,the thermal conductivity of the sample is 680.3 W/m K,and the bending strength is 277 MPa,which is better than the sample of 6 MPa（648.2 W/mk,253 MPa）.The main reason is that under the higher infiltration pressure,more B₄C is formed at the interface between diamond and copper-boron alloy,which improves the good interface bonding.（2）Under the gas pressure of 10 MPa,we compounded Cu-B（0.5wt.%）alloy with diamond particles of different size（550μm、230μm、110μm）to prepare the composites.The results show that sample with diamond particle size 550μm has the best thermal conductivity,680.3W/m K;When the temperature rises to 323 K,the thermal expansion coefficient of sample with diamond particle size 550μm is 4.91×10^-6 K^-1,higher than the thermal expansion coefficient of sample with diamond particle size 230μm,which is 4.67×10^-6 K^-1;The bending strength is 277MPa,which is lower than the sample with diamond particle size 230μm,395 MPa.