摘要
As-cast AZ91+XCa (X=0, 0.5%, 1.0%, 1.5%, mass fraction) magnesium alloys were extruded into tube at 380℃with an extrusion ratio of 6:1. The tensile properties and microstructures of extruded AZ91+XCa alloy tubes were investigated. The microstructural observation indicates that Ca can obviously refine bothα-Mg grains and Mg17Al12 phase of AZ91 magnesium alloy. XRD analysis shows that the microstructure of AZ91+0.5Ca alloy consists ofα-Mg solid solution and Mg17Al12 phase, while AZ91+1.5Ca alloy contains additionally Al2Ca phase. The tensile experimental results show that for the AZ91 alloy, the addition of Ca has little influence on the ambient temperature tensile properties but can improve the elevated temperature tensile properties. For the extruded AZ91+XCa alloys, the elevated temperature tensile strength decreases, and elongation increases with increasing the Ca content. The improvement in elevated temperature tensile strength of the alloy can be attributed to the presence of a Ca-containing phase, which can increase the microstructural stability of the alloy at elevated temperature.
As-cast AZ91＋XCa （X=0, 0.5%, 1.0%, 1.5%, mass fraction） magnesium alloys were extruded into tube at 380℃ with an extrusion ratio of 6：1. The tensile properties and microstructures of extruded AZ91＋XCa alloy tubes were investigated. The mierostructural observation indicates that Ca can obviously refine both α-Mg grains and Mg17Al12 phase of AZ91 magnesium alloy. XRD analysis shows that the microstructure of AZ91＋0.5Ca alloy consists of a-Mg solid solution and Mg17Al12 phase, while AZ9 I＋1.5Ca alloy contains additionally Al2Ca phase. The tensile experimental results show that for the AZ91 alloy, the addition of Ca has little influence on the ambient temPerature tensile properties but can improve the elevated temperature tensile properties. For the extruded AZ91＋XCa alloys, the elevated temperature tensile strength decreases, and elongation increases with increasing the Ca content. The improvement in elevated temperature tensile strength of the alloy can be attributed to the presence of a Ca-containing phase, which can increase the microstructural stability of the alloy at elevated temperature.
出处
《中国有色金属学会会刊：英文版》
CSCD
2006年第A03期1736-1740,共5页
Transactions of Nonferrous Metals Society of China
基金
Project (2002AA331120) supported by the National High Technology Research
Development Program of China (863 program)
关键词
钙
镁合金
微观结构
稳定性
张力
magnesium alloy
AZ91 alloy
tube extrusion
microstructural stability
