喷射成形制备建筑用硅质岩/A356复合材料的组织与力学性能

Microstructure and mechanical properties of siliceous rock/A356 composites for construction prepared by spray forming

采用喷射成形法制备A356铝合金和硅质岩颗粒增强A356铝基复合材料(硅质岩颗粒的质量分数为4.5%),对比了2种材料的界面组织、基体结构和力学性能。结果表明:所有硅质岩颗粒都在喷射成形阶段被捕获,并均匀分布于基体材料中。硅质岩颗粒在铝基体内形成良好的镶嵌结构,双喷电解时未发生脱落。距离颗粒/基体界面较近区域内形成较多位错,靠近界面的铝基体内Si含量较高,其余元素的含量基本保持不变。加入硅质岩颗粒后,合金的抗拉强度从603 MPa提高到662 MPa,伸长率从3.52%提高到3.92%。A356合金和硅质岩/A356复合材料均为韧性断裂,后者的拉伸断口存在硅质岩颗粒拔出后形成的凹坑,同时产生很多碎屑。

The A356 aluminum alloys and siliceous rock particles reinforced A356 aluminum matrix composites(mass fraction of siliceous rock particles is 4.5%)were prepared by spray molding.The interface structure,aluminum matrix structure and mechanical properties were compared.The results showed that all of the siliceous rock particles could be captured and uniformly distributed in the aluminum matrix during the spray forming.The siliceous rock particles formed a good mosaic structure in the aluminum matrix,and did not fall off during the double-spray electrolysis.Many dislocations were formed in the area close to the particle/matrix interface.The Si content in the Al matrix near the interface was higher,while the amount of other elements remained unaltered.Compared with A356 aluminum alloy,the tensile strength of siliceous rock/A356 composites increased from 603 MPa to 662 MPa,and the elongation increased from 3.52%to 3.92%.Both of the A356 alloy and siliceous rock/A356 composite were ductile fracture.The tensile fracture surface of siliceous rock/A356 composites was pitted by the pulled-out grains of siliceous rock,and many debris were generated.