多层喷射沉积过共晶Al-Si-Cu-Mg合金的微观组织及力学性能

多层喷射沉积技术具有冷速快、工艺简单、氧化程度低、制备的材料组织细小且分布均匀等特点．而使高硅铝合金充分发挥实用价值的关键是细化初晶硅．作者用多层喷射沉积技术制备了过共晶Al-Si-Cu-Mg合金,并与传统的铸态冶金制备的相同化学成分的合金进行了比较．对合金的沉积坯、热挤压处理后的微观组织进行了观察与分析．结果表明,多层喷射沉积合金的初晶硅大小只有25μm左右．并对合金的拉伸性能、扫描断口进行了测试与观察,提出了合金的强化与断裂机制．

Microstructures and mechanical properties of a hypereutectic Al-Si-Cu-Mg alloy by multi-layer spray deposition

Hypereutectic Al Si alloys are widely applied in aerospace, automobile and electricity industries because of its good wear resistance and low coefficient of thermal expansion. The value of hypereutectic Al Si alloys is their fine primary silicon particles. A hypereutectic Al Si Cu Mg alloy is fabricated by multi layer spray deposition technology which has more advantages than the traditional spray deposition such as higher cooling rate, simple technological route and lower oxidation. The microstructures of alloy as deposited, as extruded and after heat treatment are observed. The result shows that the primary silicon phase is fine and uniformly distributed in the matrix. The tensile properties and fracture behavior are also tested and analyzed. The strengthening and fracture mechanism are put forward at last. [