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研究了不同电源功率、拉坯速率和冷却水量等参数以及微量Sc元素对5356铝合金组织和性能的影响。结果表明,在电源功率10 k W,拉坯速率8 cm/min,冷却水量1.7 m3/h的工艺条件下,5356铝合金具有最优的表面和内部质量以及综合力学性能,抗拉强度、伸长率分别可达310.0 MPa和16.3%,且铸锭表面无明显铸造缺陷,边部组织基本为等轴晶,心部组织呈破碎枝晶形态,第二相分布均匀。5356铝合金合理的均匀化处理工艺参数为440℃,30 h,空冷,均匀化处理后合金元素Mg的微观偏析基本消除,在晶界连续分布的Al8Mg5相明显回溶。微量的Sc元素显著提高5356铝合金的强度和塑性。实验证明,5356Al+0.4%Sc(质量分数)合金晶粒明显细化,第二相数量减少,抗拉强度和伸长率达330.0 MPa和29.0%,分别提高6.5%和77.9%。
The effects of different power, billet rate, cooling water and microscale Sc on the microstructure and properties of 5356 aluminum alloy were studied. The results show that 5356 aluminum alloy has the best surface and internal quality and mechanical properties under the conditions of power of 10kW, billet rate of 8 cm / min and cooling water volume of 1.7 m3 / h. Tensile strength, elongation The length of the ingot was up to 310.0 MPa and 16.3% respectively. There was no obvious cast defects on the surface of the ingot. The edge structure was almost equiaxed, the heart structure was broken dendrite and the second phase was evenly distributed. 5356 aluminum alloy reasonable homogenization process parameters 440 ℃, 30 h, air cooling, homogenization of Mg alloy micro-segregation basically eliminated, the grain boundary continuous distribution of Al8Mg5 phase was significantly back-dissolved. Trace Sc elements significantly improve the strength and ductility of 5356 aluminum alloy. The experimental results show that the grain size of 5356Al + 0.4% Sc alloy is obviously refined, the number of second phase is reduced, and the tensile strength and elongation reach 330.0 MPa and 29.0%, which increase by 6.5% and 77.9% respectively.