【摘要】 对采用轧制复合法制备的发泡预制坯的粉末冶金发泡过程进行了研究,确定了制得的泡沫铝夹心板的组织及物相,分析了发泡剂TiH2颗粒尺寸及团聚对发泡效果的影响.研究结果表明:轧制坯充分发泡后,泡壁主要有Al3.21Si0.47,Ti及Ti3O相,Ti和Ti3O颗粒同泡壁结合紧密;预制坯内大尺寸发泡剂TiH2颗粒的周围易形成微裂纹,发泡时裂纹的宽度可扩展至100μm以上,裂纹周围的泡孔发育不良;混料及轧制阶段形成的TiH2团聚导致局部发泡驱动力过大,发泡后芯层内易形成大尺寸泡孔.更多还原

【Abstract】 The precursors for aluminum foam sandwich(AFS) were made by rolling bonding,then they were further worked through powder metallurgy-foaming process to produce AFS.The foaming process was investigated to analyze the AFS microstructure and the different phases,as well as the effects of the foaming agent TiH2 particle size and the agglomeration of those particles on foam formation.The results showed that after foaming the bubble walls are mainly composed of the Al-Si eutectic phase Al3.21Si0.47,Ti and Ti3O,and microcrackes are more likely to take place around the large-size TiH2 particles with the expandable crack width over 100 μm.Furthermore,the sizes of the pores near the cracks are very small.Agglomeration of TiH2 particles during powder mixing and rolling may result in partial excessive driving force for foaming in AFS,thus enabling the large-size pores to form in AFS core after foaming.更多还原