Al-Mg/Al_2O_3粒子复合材料的研究

A Study of Al-Mg/Al_2O_3 Particle Composite

本文研究了 Al-Mg/Al_2O_3粒子复合材料的制备工艺及其对机械性能的影响,结果表明,用两步复合法制成的复合材料中 Al_2O_3颗粒在基体中分布均匀.用该法常压铸违的复合材料拉伸断裂时,裂缝沿 Al_2O_3颗粒与基体界面发生和发展,其硬度和强度提高不大,如进行热轧硬度有所提高,但会导致 Al_2O_3拉子破裂,两相界面税开,拉伸断裂强度反而降低.经重熔压力铸造的 Al_2O_3颗粒与基体材料结合良好,拉伸断裂以切断 Al_2O_3颗粒方式进行,强度、硬度和塑性均最高.

This paper deals with the manufacturing technology and the mechanical properties of Al—Mg/Al_2O_3 particle composite.The results showd that the particle Al_2O_3 homogeneously dispersed in the composite.The phenomenon of element Mg concentrated on the boundary between particles Al_2O_3 and matr- ix was examined by EDS,but no phase has been found by X-ray diff- actometer except Al_2O_3 and α-Al matrix.The manufacturing technology aff- ected the mechanical properties of composite.For the composite produced with two-step compound method then normal cast,as tensile fracture,the crack presented and developed along the boundary between particles Al_2O_3 and martrix,the hardness and tensile strength were increased only a little. If the composite metioned above was heat milled at temperature 460℃ the tensile strength would be decreased,which related to the particle Al_2O_3 fracture and disconnected from the matrix as milling.The composites produced by twostep compound followed remelting and press casting have greater hardness, tensile strength and plastics due to the particts Al_1O_3 connected with the matrix well and cracks presented in the matrix were not along the boundary between particles Al_2O_3 and matrix.