半固态原料质量与产品性能的控制

综合分析了电磁搅拌法制浆工艺参数、成型工艺方法和半固态成型工艺参数对半固态原料质量或产品性能的影响。指出在电磁搅拌工艺中 ,搅拌速度、金属冷却速率和搅拌时间是影响半固态原料质量的 3个主要工艺参数。适当地增大搅拌速度 ,提高冷却速率 ,以及适当控制搅拌时间会使一次相晶粒变得细小 ,形状近似球状。半固态成型工艺主要分浆料成型和坯料成型。与浆料成型相比 ,坯料成型操作简单 ,便于控制 ,易于实现自动化 ,更适合于专业化生产 ,但浆料成型因节约能源 ,流程短 ,设备更简单 ,而将成为金属半固态成型技术今后的一个重要发展方向。在半固态成型中 ,比压、充型速度、保压时间和模具预热温度是影响产品组织性能的主要工艺参数。增大比压 ,提高模具预热温度 ,加大充型速度和增加保压时间会提高产品内部组织致密性 ,使产品轮廓清晰 ,尺寸精确。

Qualiy and Properties Control of Semi - Solid Forming Product and Primary Matirial

Processing parameters of slurry made by electro-magnetic stirring,processing methods and processing parameters of semi-solid forming which affect the quality of primary material for semi-solid forming and the properties of the product are generally analyzed.Three main processing parameters affecting primary material of semi-solid are stirring velocity,cooling rate of metal and stirring time.Increasing stirring velocity,upgrading cooling rate and decreasing stirring time properly will make the first phase grains smaller and the grains rosette-like.Semi-solid forming process are divided into the forming of slurry and the forming of billet.Compared with the forming of slurry,the forming of billet is fit to be produced in the form of specialization because it is manipulated and controlled easily,and is automotive.Furthermore the forming of slurry becomes an important development trend in future because it saves energy,shortens processing flow and makes equipments simple.In semi-solid processing the parameters affecting the microstructure and properties of the products are chiefly press,filling velocity,holding time and mould heated temperature.Increasing press,mould heated temperature,filling velocity and holding time can improve the interior microstructure dense,make the figure of the product clear and make its size accurate.