SiCp表面化学镀对SiCp/Al复合材料微结构及热性能影响

Effect of SiCp electroless plating on the microstructure and thermal properties of SiCp/Al composites

为了改善SiCp与Al基体之间的界面,在碱性条件下,甲醛作为还原剂,采用化学镀的方法在SiCp表面沉积铜层,然后采用无压渗透方法制备SiCp/Al复合材料.采用X射线衍射仪、3D立体视频显微镜、扫描电子显微镜来分析化学镀后SiCp和复合材料的表面、界面形貌、组织结构及物相,并通过EDS能谱对复合材料表面元素成分分析,利用激光闪光法测定复合材料导热系数.结果表明,相比酒石酸钾钠单一络合剂,采用酒石酸钾钠和EDTAG2Na组成的双络合剂的SiCp镀层更致密,且镀层未被氧化,复合材料界面结合良好,界面厚度为2.5-3μm,有AlCu2相生成,无Al4C3脆性相存在.室温下,镀铜后的复合材料热导率达到181W/（m·K）,远高于没有表面改性的复合材料热导率102W/（m·K）.

In order to improve the interface of between SiC particles and Al matrix,under alkaline condition,the surface of Si C particles was plated with Cu using electroless plating. Then SiCp / Al composites were prepared by pressureless infiltration technology. Surface and interface morphology,microstructure and phase of Si C particle and SiCp / Al composites were analyzed by X-ray diffraction,3D stereo video microscope and scanning electron microscope respectively. The surface element of Si C particles coating and composites was analyzed by EDS,meantime,thermal conductivity of SiCp / Al composites was measured by the laser flash method. The results show that,compared with a single KNa C4H4O6·4H2O complexant,double complexants( KNaC4H4O6·4H2O + EDTA-2Na) can more effectively plate a dense,no oxidation and good combined interface Cu coating on the surface of SiCp. The interface thickness of Cu was approximatively 2. 5-3μm. AlCu2 phase was detected in the interface,however Al4C3 brittle phase was not found. The thermal conductivity of SiCp / Al composites was 181 W /( m·K) at 20 ℃. It was much higher than that( 102 W /( m·K)) of SiCp / Al composites without surface modification of SiCp.