In this work, a 6061-SiC composite was prepared using the compound casting method and then processed using a vacuum-assisted high-pressure die-casting technology under fast shot speeds of 1, 2 and 3 m/s, respectively. The effect of fast shot speed and wall thickness on the skin layer, porosities and mechanical properties were studied. The results showed that, with the increase of the fast shot speed, the thickness of the skin layer was decreased significantly. The porosities of the samples were decreased first and then increased with the increase of wall thickness. The pore number in the 4-mm sample was the smallest, while the pore number in the 8-mm sample was the largest, with many large-sized strip shrinkage pores. Under a fast shot speed of 1 m/s, the large-sized pores and the skin layer (~ 0.5 mm) led to the brittle fracture and low tensile properties of the sample. When the fast shot speed was increased to 3 m/s, the defects of the microstructures mentioned above were improved, and the sample’s tensile properties were further improved.

在这项工作中，使用复合浇铸方法制备了 6061-SiC 复合材料，然后使用真空辅助高压压铸技术在 1、2 和 3 m/s 的快速注射速度下进行加工。研究了快速射出速度和壁厚对表层、孔隙率和机械性能的影响。结果表明，随着快速射出速度的增加，表层厚度显着减小。试样的孔隙率随着壁厚的增加先减小后增大。4-mm样品中的孔数最少，而8-mm样品中的孔数最大，有许多大尺寸的条状收缩孔。在 1 m/s 的快速射速下，大尺寸的毛孔和皮肤层（~0. 5 mm) 导致样品脆性断裂和低拉伸性能。当快射速度提高到3 m/s时，上述显微组织的缺陷得到改善，试样的拉伸性能进一步提高。