半固态A356合金的流变压铸充填性与组织分布

Filling Ability of Semi-solid A356 Alloy in Rheo-casting and Microstructure Distribution

试验研究了压射比压和压射速度对半固态A356铝合金流变压铸充填性的影响。试验结果表明:压射比压和试片的壁厚对新型方法制备的半固态A356合金浆料的充填性影响较大,试片壁厚越大,压射比压越大,型腔越容易充满;为了保证充满型腔,对于10mm的试片,压射比压应≥15MPa,而对于5mm的试片,压射比压应≥20MPa。压射速度对半固态A356合金浆料充填性也具有较大的影响,较高的压射速度有利于半固态A356铝合金浆料的充填;为了保证充满型腔,对于10mm的试片,压射速度应≥0.384m/s,而对于5mm的试片,压射速度应≥1.152m/s。流变压铸试片的组织分布很均匀,利于获得高质量的半固态A356合金压铸件。

Effects of injection specific pressure and injection speed on the filling ability of semi-solid A356 alloy in rheo-casting were investigated.It is revealed that the filling pressure and the thickness of the billets have greatly affected the filling ability of semi-solid A356 Al alloy slurry prepared by the new method.The thicker the billets is,and the bigger the filling pressure is,the better the filling ability is,and vice verse.In order to obtain perfect castings,the filling pressure for the billets with 10 mm thickness should be equal to or more than 15 MPa and for the billets with 5 mm thickness equal to or more than 20 MPa.The injection velocity has great effects on the filling ability of the semi-solid A356 alloy slurry,and that the higher the injection is,the better the filling ability of the slurry is.For making sound castings,the filling velocity for the billets with 10 mm thickness should be equal to or more than 0.384 m/s while for the castings with 5 mm thickness equal to or more than 1.152 m/s.The billets with uniformly distributed microstructure in rheo-casting are beneficial to obtaining the A356 alloy die castings with perfect quality.