自渗透制备SiC_p_Al复合材料及其耐磨性

SiC_p-Al composites produced by pressureless infiltration and their abrasion resistances

研究了以Ｋ２ ＺｒＦ６ 为助渗剂、用自渗透法制备ＳｉＣｐＡｌ 复合材料的技术． 全面考查了Ｋ２ ＺｒＦ６ 的配比、ＳｉＣｐ 粒度、温度、保温时间等工艺参数对自渗透过程的影响． 借助于复合材料金相组织的分析，认为粉体预热温度６５０ ℃，铝合金液浇注和保温温度７８０ ～８００ ℃，保温２ ｈ后随炉冷却是本试验的最佳工艺参数． 经测定，所制复合材料的硬度比基体合金提高了３６ ％～５８％ ，耐磨性提高了２～６ 倍．

Studies the fabrication of SiC p/Al composite via pressureless infiltration with K 2ZrF 6 as an infiltration promoter. The effect of process factors, including ratio of K 2ZrF 6 and SiC p, SiC p size, preheating temperature for powder preform, pouring temperature of aluminium alloy melt, and soaking temperature and duration, were investigated. According to the metallographic analysis of composites, the optimum infiltration factors were determined which consist of a preheating of powder preform at 700 ℃, pouring and soaking aluminium alloy melt at 780～800 ℃, and a two hour soaking period followed by a cooling in the furnace. Experiments show that the hardness of the composites is 36%～58% higher than the matrix alloy and their abrasive resistances increase by 2～6 times.