热处理对压铸AlSi10MnMg减震塔组织及力学性能的影响

Effects of Heat Treatment on the Microstructure and Mechanical Properties of High Pressure Die Casting AlSi10MnMg Shock Tower

采用硬度测试、拉伸测试、光学显微镜、扫描电镜及透射电镜等手段,研究了不同热处理制度对压铸AlSi10MnMg合金减震塔的组织及力学性能的影响。结果表明,T5及T6热处理可以改善减震塔的微观组织和力学性能。T5处理后组织中Si相发生球化,减震塔塑性随热处理温度升高而提升,经350℃×2h(T5)热处理后伸长率达到16.32%,较铸态的7.67%提高约100%。T6热处理后合金组织中析出Mg2Si等强化相,但尺寸随温度升高而增加,经500℃×2h+175℃×6h(T6)热处理后,材料的屈服强度为217.06 MPa,抗拉强度为294.28MPa,伸长率为10.25%。

By hardness and tensile testing,optical microscope,scanning electron microscope and transmission electron microscope,the effects of different heat treatment processes on the microstructure and mechanical properties of high pressure diecasting(HPDC)AlSi10MnMg alloy shock tower were investiagted.The results indicate that T5and T6heat treatment can improve the microstructure and mechanical properties of the shock tower.After T5heat treatment,the silicon phase in the structure is spheroidized,and the plasticity of the shock tower is increased with the increase of heat treatment temperature.After T5(350℃×2h)heat treatment,the elongation reaches 16.32%,which is twice of that of the as-cast state.After T6heat treatment,the Mg2Si and other strengthening phases can be precipitated,however the size is increased with the increase of temperature,while the strength of shock tower is decreased continuously with the rise of the temperature.After T6(500℃×2h+175℃×6h)heat treatment,the yield strength,tensile strength and elongation of the shock tower reach 217.06 MPa,294.28MPa and 10.25%,respectively.