真空变压力浸渗法制备高体积分数SiC_p/Al复合材料

Preparation of high volume fraction SiC_p/Al composites by vacuum-adjustable pressure infiltration process

采用真空变压力浸渗法制备高体积分数SiCp／Al复合材料。结果表明，真空变压力浸渗法具有良好的渗流和凝固条件，避免了气体和夹杂物的裹入等问题；在压力为0．6MPa、保压时间为15min和温度为1073K的条件下，成功渗透了振实堆积的单一尺寸SiCp多孔体的最小粒径为17μm；而32μm的SiCp多孔体浸渗后的复合材料中SiCp体积分数达到了60％。在0．4～0．6MPa和1073K的条件下浸渗15min，可渗透的最小SiCp粒径达到了10μm，其体积分数为56％。经OM、SEM、XRD分析表明，铝液渗透均匀，内部组织致密，无明显的孔洞及夹杂等铸造缺陷，界面无脆性Al4C3相生成。

The high volume fraction SiCp/Al composites were fabricated by vacuum-adjustable pressure infiltration process. The results show that infiltration and solidification are effectively promoted by vacuum-adjustable pressure infiltration process, which also avoids the gas and the inclusion binds. The preform of a single minimum SiC particle with size of 17 μm and volume fractions of 58% is successful infiltrated under pressure of 0.6 MPa, holding time of 15 min and temperature of 1 073 K. In the meantime, SiCp particles with size of 32μm and volume fraction of 60% are obtained. Furthermore, the single SiC particles with size of 10 μm and volume fractions of 56% was successful infiltrated for 15 min under condition of 1 073 K and 0.4 -0.6 MPa. The analyses results by OM, SEM, XRD indicate that SiC particles are uniformly distributed in the aluminum matrix without casting defects, such as bubble, shrinkage, inclusion, and the brittle Al4C3 phase is not found in the interracial region.