电磁搅拌与浇注温度对半固态A356铝合金中微量稀土细化初生相的影响

Influences of Electromagnetic Stirring and Pouring Temperature on the Refinement of Primary Phase by Micro-addition of RE in Semisolid A356 Alloy

在不同浇注温度和电磁搅拌制度下制备了A356铝合金半固态浆料,研究了微量稀土下浇注温度、电磁搅拌频率和时间对半固态A356铝合金初生相形貌及力学性能的影响。结果表明,通过优化半固态制浆工艺条件减少稀土的加入量是可行的,实验表明稀土微量化的合适工艺方案是:浇注温度为630℃,电磁搅拌频率为30Hz,搅拌时间为8s。此时,加入量为0.3%的稀土La细化效果和常规加入量为0.4%La的低过热度浇注的相当,其力学性能也基本相同。

The semisolid slurry of A356 alloys were prepared at different pouring temperatures and electromagnetic stirring processes. The morphologies of primary phase and mechanical properties of the semisolid A356 alloy were investigated under the pouring temperature, electromagnetic stirring frequency and treated time with the trace RE. The results showed that, it was feasible to reduce the addition amount of RE by optimizing the semisolid slurry process conditions. The suitable preparing parameters were obtained by the experiment, in which the pouring temperature was 630 ℃, the frequency of electromagnetic stirring was 30 Hz, and the stirring treated time was 8 s. At this point, when the content of La addition was 0. 3%, the modification effects of the semisolid A356 alloy was indistinguishable with the conventional addition amount of 0. 4% La in low superheat pouring, and their mechanical properties were close to each other.