中文摘要：

效果压榨在微观结构和高级低共熔体的 Al-xSi 合金的机械性质上扔(x=15， 17.5， 22wt%) 在这研究被调查。高级低共熔体的 Al-xSi 合金的微观结构显然是的结果表演改善了由压榨扔。粗糙的主要 Si 阶段的数量减少了，当好主要 -Al 树突的随增加增加了时压榨扔压力。虽然扔合金的 squeeze 的好微观结构，和机械性质被改进，由于粗糙的主要 Si 粒子的减少，矩阵裂开被减少。与扔合金的严肃相比，高级低共熔体的 Al-xSi 合金的机械性质在 600MPa 团结了显著地被改进。扔高级低共熔体的 Al- 的 squeeze 的坚硬(15， 17.5， 22wt%) Si 合金被 15.91% 改进， 12.23% ， 17.48% ，最终的张力的力量被 37.85% 改进， 32.27% ， 22.74% ，并且延伸被 55.83% 改进， 167.86% ， 126.76% 分别地。由于 Si 阶段在的一致分发压榨扔 Al-xSi 合金，他们的 wear 抵抗显著地被提高。

英文摘要：

The effect of squeeze casting on microstructure and mechanical properties of hypereutectic Al-xS i alloys（x = 15, 17.5, 22 wt%） was investigated in this study. Results show that microstructure of the hypereutectic Al-x Si alloys was obviously improved by squeeze casting. The amount of coarse primary Si phase decreased, while that of fine primary α-Al dendrites increased with the increase of squeeze casting pressure. Due to the decrease of coarse primary Si particles, cracking of the matrix was reduced, whilst the fine microstructure, and mechanical properties of the squeeze casting alloys were improved. Compared with gravity casting alloys, mechanical properties of the hypereutectic Al-xS i alloys solidified at 600 MPa were improved significantly. Hardness of the squeeze casting hypereutectic Al-（15, 17.5, 22 wt%） Si alloys was improved by 15.91%, 12.23%, 17.48%, ultimate tensile strength was improved by 37.85%, 32.27%, 22.74%,and elongation was improved by 55.83%, 167.86%, 126.76%, respectively. Due to the uniform distribution of Si phases in squeeze casting Al-x Si alloys, their wear resistance was markedly enhanced.