【摘要】 由一对带有螺纹的内外桶的旋转 ,在其间的缝隙形成剧烈的剪切应力场的作用原理自行研制的镁合金浆料制备装置。内外桶缝隙控制在 1～ 3mm。通过控制桶的转速可以获得 0～ 10 0s- 1 剪切速率 ,剪切时的温度在 5 0～ 90 0℃之间任意调节。通过计算分析 :AZ91合金的半固态流变成形温度区间为 5 5 0～ 5 90℃ ,同时得到了AZ91合金的固相体积分数fs(固相率 )随温度变化的关系曲线。此外还确定了转速与剪切速率的关系。在温度为 5 70℃ ,固相体积分数为 0 .41时 ,不同的剪切速率条件下镁合金浆料制备与压铸的实验结果表明 :利用该装置制备出的半固态浆料晶粒圆整 ,组织均匀 ,并随着剪切速率的提高固相颗粒更加细小均匀。更多还原

【Abstract】 Based on the principle concentred the flow of metal slurry in gap between the two rotating tubes with groove showing high shear stress field, the equipment used in preparation of the semi solid magnesium alloy was developed and the new approach of how to develop magnesium alloy was explored. The gap of metal slurry flowing can be changed from 1.0 to 3.0 mm. The most shear rate is 100 s -1 and the shear temperature is controlled between 50 ℃ and 900 ℃. The temperature range of the semi solid of AZ91 magnesium alloy and the change of the fraction of solid phase volume with temperature were obtained by model analysing and calculating. The relationship between the shear rate and the rotate speed of motor was also determined. The slurry of the semi solid was prepared and AZ91 magnesium alloy was rheocasted by means of the equipment in different shear rate when the temperature was 570 ℃ and the fraction of solid phase volume was 0.41. The experiment results show that the semi solid slurry′s grain is near round in shape and with the increase of shear rate, the grain is smaller.更多还原