【摘要】 采用双螺杆机械搅拌法制浆技术与半固态流变压铸成形工艺相结合,直接在压铸机的压射室中成功地制备出优质半固态镁合金坯料,极大地节约了模具的开发费用。坯料的初生α-Mg相细小、圆整,且晶粒平均尺寸为40~60μm。电子探针分析结果表明:坯料微观组织中未见明显的溶质扩散层,在细小的网状共晶相中析出了大量的晶粒尺寸为5~10μm的二次α-Mg相;半固态流变压铸成形工艺在提高铸件致密度的同时,也提高了铸件的硬度,与液态压铸成形试样相比,其密度提高了0.33%,硬度提高了4.6%。更多还原

【Abstract】 With the combination of semi-solid slurry preparation by twin-screw stirring and rheo-diecasting process,an excellent semi-solid feedstock of magnesium alloy was successfully produced.The primary α-Mg phase is fine and round,and the average size of grains is 40μm⁶0μm.The technique reduces distinctly the cost of die exploitation due to processed directly in the inject chamber of die casting machine.No obvious solute diffusion layer is discovered on the solidified microstructure of semi-solid sample by EDS analysis,and many fine secondary α-grains of 5¹0μm in diameter are found within lamellar Mg₁₇Al₁₂.At the same time,the results indicate that the density and hardness of semi-solid feedstock of magnesium alloy are increased in comparison with the samples fabricated by conventional die casting,the density and hardness are increased by 0.33% and 4.6%,respectively.更多还原