Preparation and characterization of aluminum foams with ZrH₂ as foaming agent

来源期刊：中国有色金属学报(英文版)2011年第2期

论文作者：李大武 李杰 李涛 孙挺 张小明 姚广春

文章页码：346 - 352

关键词：泡沫铝；氢化锆；气泡；熔体发泡法

Key words：aluminum foams; zirconium hydride; bubble; melt-based route

摘    要：使用氢化锆为发泡剂，通过熔体发泡法制备泡沫铝并研究其影响因素。制备工艺为：添加0.6%？1.4%的发泡剂，1.5%？3.0%Ca(质量分数)作为增粘剂，发泡温度933？1 013 K，搅拌时间为0.5？2.5 min和保温时间为1.5？4.0 min。利用XRD和SEM对泡沫铝样品进行表征，测试其力学性能。结果表明，在合适的工艺参数下能制备出孔径均匀的泡沫铝，采用氢化锆为发泡剂可以制备出平均孔径为1 mm左右的泡沫铝。金属间化合物和Al₂O₃的存在影响熔体的粘度。泡沫铝的力学性能经历线弹性区、平台区和致密化区并表现出较高的能量吸收效率。

Abstract: Aluminum foams were fabricated by melt-based route using ZrH₂ as a foaming agent. The factors which affected the foaming of aluminum foams during casting process were investigated. The powdered zirconium hydride with content of 0.6%-1.4% (mass fraction) was added to the molten pure aluminum and the foaming condition was controlled in a temperature range from 933 to 1 013 K, Ca amount of 1.5%-3.0% (mass fraction), stirring time of 0.5-2.5 min and holding time of 1.5-4.0 min to obtain homogeneous aluminum foams. The fabricated aluminum foams were characterized by XRD, SEM and Image-pro plus. The mechanical properties of the aluminum foams with different relative density were tested. The result indicates that the foaming agent (ZrH₂) is suitable for the preparation of small aperture aluminum foams with average pore diameter of 1 mm. Inter-metallic compounds and Al₂O₃ have effect on the melt viscosity. The aluminum foams experience linear elastic, platforms and densification process and had a higher efficiency of energy absorption.