摘要
研究了稀土镧对AZ91合金的显微组织和硬度的影响。结果表明:加入稀土镧后,AZ91合金铸态晶粒细化,且Mg17Al12相减少;大部分镧与铝结合生成高熔点、高热稳定性的针状稀土相 (Al11La3 ),从而改善晶界相的分布,提高铸态宏观硬度;固溶 +时效处理后,在晶界处析出片层状Mg17Al12相。随时效时间的延长,硬度进一步增加。
The effect of La on microstructure and macro-hardness of AZ91 alloy was studied in the paper. The experiment shows that addition of La results in as-cast grain refinement and the amount of Mg_(17)Al_(12) phase decreases. Most of La reacts with aluminum to form needle compounds of Al_(11)La_3 with high melting point and elevated temperature stability in the grain boundary,and the macrohardness of as-cast is improved. After solid solution and aging treatment, sheet Mg_(17)Al_(12) phase separates out in the grain boundary. With the increase of aging time,the macro-hardness of AZ91 alloy further increased.
出处
《铸造设备研究》
2005年第1期20-22,共3页
Research Studies On Foundry Equipment
基金
山西省自然科学基金项目(20011047
20021052)。
