【作者】 郭莉军；

【导师】 谭建波；

【作者基本信息】 河北科技大学 ， 材料加工工程， 2011， 硕士

【摘要】 半固态流变成形技术的独特优势是工艺流程短、生产成本低、生产效率高,这些优点符合当今时代节能减排和绿色铸造的要求。近些年来半固态流变成形技术已经成为了半固态成形技术的发展趋势。而在半固态成形技术中,半固态合金的制备技术一直是国内外半固态成形技术领域研究的一个热点。本文利用自主设计制造的带有扰流柱的倾斜流变装置制备半固态AlSi9Mg合金。研究了浇注长度、斜槽倾斜角度、扰流柱形状、扰流柱排列形式及扰流柱排列间距对半固态AlSi9Mg合金组织的影响。并且探讨了不同振动维数和振动频率对半固态AlSi9Mg合金组织的影响。研究结果表明:合金浇注温度为615℃,浇注长度为400mm,斜槽倾斜角度为45°时可以制备出比较理想的半固态AlSi9Mg合金。扰流柱参数对半固态AlSi9Mg合金组织的影响较大;在本试验条件下,最佳的扰流柱形状为水滴形、排列形式为叉排、排列间距为排间距S=15mm,列间距L=40mm,制备的半固态AlSi9Mg合金的微观组织特征为:初生固相率为53.54%,晶粒尺寸为5.59μm,圆整度为0.61。振动维数对半固态AlSi9Mg合金组织的影响较大;二维振动优于一维振动,在本试验条件下,XZ方向振动,振动频率为40Hz时,制备的半固态AlSi9Mg合金的微观组织特征为:初生固相率为37.56%,初生固相率的晶粒尺寸为5.53μm,圆整度为0.57。振动频率对半固态AlSi9Mg合金组织的影响较大;三维振动时,在本试验条件下,振动频率为30Hz时,制备的半固态AlSi9Mg合金的微观组织特征为:初生固相率为56.32%,晶粒尺寸为4.07μm,圆整度为0.51。更多还原

【Abstract】 The greatest advantage of semi-solid rheological forming process is process flow short, low production costs and high production efficiency, which is in line with the requirements of Energy-saving and emission reduction and Green casting. In recent years it has become a major trend of semi-solid forming technology. In the semi-solid forming technology, the preparation of semi-solid alloy has been a hot research field at domestic and abroad.In this paper, water quenched samples of AlSi9Mg are prepared by using the self-designed Tilt rheological device with the Turbulence column. Pouring length, Angle of inclination, Shape of the pin fins, Forms of pin fins arrangement and Pin fins arrangement spacing are studied to find how they affect the microstructure of AlSi9Mg semi-solid alloy. Different vibration frequency and vibration dimension are studied to find the effect of the microstructure of semi-solid AlSi9Mg alloy. The results showed that:When pouring temperature is 615℃, Pouring length is 400mm,and angle of inclination is 45°, the obtained of semi-solid AlSi9Mg alloy melt is nearly ideal.Pin Fins parameters have great effect on the microstructure of semi-solid AlSi9Mg alloy. In this experiment, when the shape of Pin Fins is Droplets form, the form of Pin fins is arrange staggered, Row spacing S2 is 15mm, and column spacing L2 is 40mm, we can get good microstructure. Its solid fraction is 53.54%, grain size 5.59μm, and shape factor is 0.61.Vibration dimensions have great influence on the microstructure of semi-solid AlSi9Mg alloy, and we discover that two-dimensional vibration was better than one-dimensional vibration. In this experiment, when vibration is XZ direction with the vibration frequency of40Hz,we can get good microstructure. Its solid fraction is 37.56%, grain size is 5.53μm, and shape factor is 0.57.Vibration frequency has great influence on the microstructure of semi-solid AlSi9Mg alloy. When the three-dimensional vibration with the frequency of 30Hz, we can get good microstructure. Its solid fraction is 56.32%, grain size is 4.07μm, and shape factor is 0.51.更多还原