Effects of La on the Microstructures and Mechanical Properties of AZ91 Magnesium Alloy and Its Mechanism

摘要：

Microstructure changes brought by the addition of La element to AZ91 magnesium alloy are studied, also, the precipitating phases were identified and their influence on the mechanical properties of alloys was investigated. Results show La makes refinement of microstructure of the AZ91 alloy, and decrease the size of Mg17Al12 phase. La element takes a priority to react with Al element over Mg, forming binary phase Al11La3 with high melting point. Certain amount of La increases tensile strength, yield strength and elongation. With more addition, La would combine more Al in matrix and decrease strengthening effect, because Al11iLa3 phase would become coarsening. The mechanical poroerties tests indicate that AZ91+0.16％ La alloy has the best properties. Maximum tensile strength, maximum yield strength and elongation are 245MPa, 178MPa and 14.5％ respective, increased by 21％, 19％ and 48％ respectively. The mechanism of La strenthing mechanical properties is proposed that Al11 lLa3 phase enriched on solid-liquid interface, increased the degree of supercooling, refined the grain size and changed the crystal style.

关键词： AZ91 Rare earth La Degree of supcooling Microstructure Mechanical properties

作者: Jinling Zhang Shebin Wang Xiaoye Qi Bingshe Xu

作者单位: Key laboratory of interface science and engineering in advanced materials, ministry of education, Ta Taiyuan University of technology, college of material science and technology, Taiyuan P.R.China, 030

会议类型: 国际会议

会议名称: 2011 International Conference on Mechatronics and Materials Processing(2011年机电一体化与材料加工国际会议 ICMMP)

会议地点: 广州

会议语种:英文

页码: 1650-1653

在线出版日期: 2011-11-18（万方平台首次上网日期，不代表论文的发表时间）