TBR工艺对AZ91D镁合金压铸件组织性能的影响

Influence of taper barrel rheomoulding on microstructure and mechanical properties of AZ91D magnesium die casting

采用自主研发的锥桶式流变成型技术,实现AZ91D镁合金从制浆到流变压铸的一体化工艺过程。研究TBR工艺下AZ91D镁合金流变压铸件的显微组织、力学性能及拉伸断口,探讨TBR工艺参数对流变压铸件微观组织与力学性能的影响规律。结果表明,流变压铸AZ91D镁合金合适的TBR工艺参数是内锥桶转速为500-600 r/min、外锥桶桶体温度为570-590℃;与液态压铸相比,TBR工艺下流变压铸件抗拉强度提高了5%-15%、伸长率提高40%以上,拉伸断裂方式由沿晶断裂占主导转变为以准解理断裂占主导。

With an independently developed taper barrel rheomoulding（TBR） technology,a new rheo-diecasting process is able to be used to produce semi-solid AZ91D magnesium alloy components with more excellent performance.The influences of TBR process parameters,the rotation rate of internal barrel and the temperature of external barrel on the microstructure of semi-solid AZ91D magnesium alloy components are studied;the mechanical properties of these products are tested and evaluated.The results indicate that the most suitable TBR process for the rheo-diecasting are 500-600 r/min and 570-590 ℃.Thanks to the optimization of the microstructure,the tensile strength has increased by 5%-15%;the percentage elongation after fracture has increased by 40%;the quasi-cleavage fracture is predominant in rheo-diecasting AZ91D magnesium alloy,while normal die casting AZ91D magnesium alloy parts along the grain as a large proportion.