铝、镁合金半固态浆料的制备与流变成形新工艺

介绍了阻尼冷却管法制备A356铝合金半固态浆料工艺的实验装置及其原理,并进行不同浇注温度的系列实验。结果表明:由于阻尼冷凝管的冷却和搅拌作用,熔体浇注温度越低,在两相温度区间内生成的游离晶核就越多,制备得到半固态铸件的晶粒尺寸就越小,且球化程度越高。在此实验原理及结果分析的基础上,设计真空吸铸-阻尼冷却装置,近液相线温度的AZ91D镁合金液在冷却、剪切的作用下,由液态转变为半固态浆料,然后进入模具完成充型,实现镁合金半固态浆料的制备与铸件流变成形一体化;半固态镁合金熔体具有触变性及更高的黏度,以平稳、层流的充型方式完成充型,能够有效地改善成形件的质量。

Novel process for fabrication and rheoformation of aluminum and magnesium alloys semisolid slurry

The setup and principle of damper cooling tube(DCT) process,which is used to prepare semisolid slurry of A356 aluminum alloy in different pouring temperatures,were introduced.The results show that the microstructures are directly related to the pouring temperature,the lower pouring temperature is,the more stray nuclei produced are,the smaller grain size is and the bigger shape factor is.On the basis of the experimental results and principle,a novel semisolid processing technique,called vacuum suction casting-damper cooling tube(VSC-DCT) process,is used to manufacture high quality components of AZ91D Mg-alloy directly from a near-liquidus metal.The outstanding feature of this investigation is attributed to the fact that the VSC-DCT process combines the semi-solid slurry making and component forming operation into one step,therefore,eliminating the need for specially prepared slurry and subsequent slurry transportation steps.The semisolid metal with higher viscosity can be caused to fill the mold with solid-front fill,and the surface quality of the sheets fabricated by the VSC-DCT method is improved significantly.