一种采用气冷搅拌杆流变压铸工艺制备的Al-8Si合金的组织与性能（英文）

发布时间：2018-11-03 10:18

【摘要】：报道了一种新颖、高效的采用气冷搅拌杆制备半固态浆料的工艺,该工艺通过将压缩空气不断注入到搅拌杆内腔来冷却熔体。采用该工艺制备了一种新近研发的高导热Al-8Si合金半固态浆料,并将该工艺与高压铸造机结合生产出一种无线基站用薄壁散热壳体件。研究了气体流量对初生晶粒的形貌、流变压铸件的力学性能及导热系数的影响。结果表明:当气体流量超过3 L/s时,采用该工艺可以制备出优质的半固态浆料。当气体流量为5 L/s时,流变压铸件的力学性能和导热系数最高,分别为抗拉强度261 MPa,屈服强度124 MPa,伸长率4.9%,显微硬度HV 99和导热系数153 W/(m·K)。相比于传统压铸件,采用气冷搅拌杆流变压铸工艺生产的铸件力学性能和伸长率大大提高,其抗拉强度、屈服强度、伸长率、显微硬度和导热系数的增长率分别为20%、15%、88%、13%和10%。
[Abstract]:A novel and efficient process of preparing semi-solid slurry with air-cooled stirring rod is reported. The process is to cool the melt by continuously injecting compressed air into the inner cavity of the rod. A newly developed semi-solid slurry of high thermal conductivity Al-8Si alloy was prepared by this process, and a thin wall heat dissipation shell for wireless base station was produced by combining this process with high pressure casting machine. The effects of gas flow rate on the morphology of primary grains, mechanical properties and thermal conductivity of rheological die castings were studied. The results show that the high quality semi-solid slurry can be prepared by this process when the gas flow rate exceeds 3 L / s. When the gas flow rate is 5 L / s, the mechanical properties and thermal conductivity of rheological die castings are the highest, which are tensile strength 261 MPa, yield strength 124 MPa, elongation, microhardness HV 99 and thermal conductivity 153W / (m K)., respectively. Compared with traditional die castings, the mechanical properties and elongation of the castings produced by air-cooled mixing rod rheological die-casting process are greatly improved. The growth rates of tensile strength, yield strength, elongation, microhardness and thermal conductivity are 2015%, respectively. Thirteen percent and ten percent.
【作者单位】：北京科技大学材料科学与工程学院;北京科技大学材料先进制备技术教育部重点实验室;
【基金】：Project (2013B091300016) supported by the Department of Science and Technology of Guangdong Province,China
【分类号】：TG146.21;TG249.2

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