金刚石/铜复合材料的SPS扩散连接界面组织及力学性能

Microstructure and Mechanical Properties of SPS Diffusion-bonded Interface of Diamond/Cu Composites

对金刚石/铜复合材料进行SPS扩散连接试验,并对其连接接头进行了界面扩散分析和剪切性能测试,研究了SPS扩散连接工艺参数对连接界面组织和力学性能的影响。结果表明,随着连接温度升高和保温时间增加,金刚石/铜连接接头扩散界面区域的孔洞和空隙等缺陷减少,元素扩散充分,W逐渐向Cu方向扩散,与母材相比,连接界面W2C相和W相减少。随着扩散连接品质提升,热导率随之增加,焊接接头的最大剪切力和剪切强度增大,剪切断面形貌逐渐产生大量解理面和断裂台阶,并伴有少量撕裂棱,断裂机制由脆性过渡到半解理韧性断裂。扩散温度为750℃,保温时间为90 min时,连接界面整体扩散结合品质较高,剪切强度达到48.83 MPa,热导率为347.73 W/(m·K)。

SPS diffusion bonding tests were carried out on the diamond/copper composite, and the interface diffusion analysis and shear performance test were conducted on the joints. The effects of SPS diffusion bonding process parameters on the microstructure and mechanical properties of the bonding interface were investigated. The results indicate that with the increase of bonding temperature and sintering time, the defects such as holes and voids in the diffusion interface area of diamond/copper joint are decreased, and the element diffusion is sufficient with tungsten gradually diffusing to the copper direction, and the W2C phase and W phase in the bonded interface are reduced compared with the base metal. With the improvement of diffusion bonding quality, the thermal conductivity, maximum shear force and shear strength of bonded joints are increased, and a large number of cleavage planes and fracture steps are gradually generated on the shear section, accompanied with a small number of tear edges. The fracture mechanism is transformed from brittle fracture to semi-cleavage ductile fracture. When the diffusion temperature is 750 ℃ and the sintering time is 90 min, the bonding interface presents a satisfied element diffusion effect and maintains a high thermal conductivity[347. 73 W/(m·K)], where the maximum shear strength reaches 48. 83 MPa.