半固态AlSi7Mg铝合金的新型流变成形

New rheocasting technology of semi-solid AlSi7Mg alloy

采用新型流变成形技术,研究了压射比压与压射速度对半固态AlSi7Mg铝合金流变压铸过程的影响．结果表明:将低过热度浇注与短时弱电磁搅拌相结合,能制备出均匀的半固态AlSi7Mg铝合金浆料,适合流变压铸,流变成型参数范围较宽,有利于提高压铸件的质量．试片的璧厚、压射比压和压射速度都对半固态AlSi7Mg合金浆料的充填性有较大的影响．对于10 mm的试片,压射比压应≥15 MPa,压射速度应≥0．384 m／8;而对于5 mm的试片,压射比压应≥20 MPa,压射速度应≥1．152 m／8．

The new technology for preparing semi-solid slurry of AISi7Mg alloy and influence of specific pressure and injection speed on the rheodiecating process was investigated. The results show that the slurry prepared by low superheat pouring and weakly electromagnetic stirring for a short time is very homogeneous, and the rheodiecasting technological parameters are wider and helpful to obtain semi-solid castings of high quality. The thickness of the casting piece, the injection pressure and the injection speed have great influence on the filling ability. For 10 mm thick piece, the injection pressure should be equal to or more than 15 MPa, the injection speed should be equal to or more than 0.384 m/s; but for 5 mm thick piece, the injection pressure should be equal to or more than 20 MPa, the injection speed should be equal to or more than 1.152 m/s.