【摘要】 采用二次发泡新方法制备具有致密表层的泡沫铝合金球形件,通过微型CT层析摄像仪对制备获得的泡沫铝合金球形件的孔结构形态进行观察和分析.研究了二次泡沫化温度和时间等参数对球形件孔结构(孔径,孔隙率)的影响,分析了球形件充型过程中的作用机理.结果表明,TiH2的二次分解是泡沫铝球形件充型驱动力,采用合适温度和时间通过二次泡沫化方法可制备孔结构均匀、具有致密表层外皮的泡沫铝合金球形件,孔隙率范围可在50.4%~93.8%变化,充型过程是固-液-气三相的共同作用.更多还原

【Abstract】 Foamed aluminum alloy spherical parts with dense skins were fabricated with a secondary-foaming method.Their pore structure was scanned and analyzed with XCT.The effects of foam temperature and time on pore structure(diameter,porosity) were experimentally investigated.The mechanics of the molding process were then analyzed.The results showed that filling ability is dominated by redecomposition of TiH2.With appropriate temperatures and times,the secondary-foaming method can produce foamed Al alloy spherical parts with dense skins and between 50.4%~93.8% of porosity.The molding process is the joint action of solid-liquid-gas phases.更多还原