AlSi12合金泡沫的真空发泡制备工艺  

Vacuum Foaming Fabricating Processing of AlSi12 Alloy Foam

作　　者：杨皓[1] 左孝青[1] 王俊[1] 陆建生[1] 周芸[1] Yang Hao Zuo Xiaoqing Wang Jun Lu Jiansheng Zhou Yun(Kunming University of Science and Technology, Kunming 650093, Chin)

机构地区：[1]昆明理工大学,云南昆明650093

出　　处：《稀有金属材料与工程》2016年第11期2992-2998,共7页Rare Metal Materials and Engineering

基　　金：国家自然科学基金项目(51164019);云南省应用基础研究重点项目(2010CC004)

摘　　要：为克服现有熔体发泡制备泡沫铝工艺中发泡剂TiH_2含量高所带来的成本高、分散性差、与发泡工艺匹配难、降低材料性能等负面影响,采用新型真空发泡法制备Al Si12合金泡沫,并对其中的初始气孔及真空发泡AlSi12合金泡沫孔结构的形成及控制工艺进行研究。结果表明:AlSi12合金在620℃熔化保温1 h、添加1%Si C和2%Ca以2000 r/min的速度搅拌10 min增粘、添加微量(0.02%,质量分数)Ti H2以2000 r/min的速度搅拌6 min的条件下可获得均匀细小的初始气孔;在真空度为5 Pa下发泡10 s,真空下冷却6 min的条件下,获得了平均孔径2.4 mm,孔隙率83.7%,孔结构均匀的AlSi12合金泡沫;初始气孔以SiC、Al_2O_3、SiO_2等第二相为气泡非均质形核的核心。Now aluminum foam fabrication demands too much TiH2 as a foaming agent, which causes high cost, poor dispersion, difficulty to match the foaming process and the performance degradation of the material. Therefore, in the present paper, a new vacuum foaming processing was employed to prepare AlSi12 alloy foams to overcome these shortcomings. The initial pores, the cell structure and the processing of the vacuum foamed AlSi12 were studied. The results show that initial fine pores of well-distribution are obtained by the processing as follows： melting Al Si12 alloy at 620 °C for 1 h, adding 1% Si C and 2% Ca into the melt and stirring the melt for 10 min at the stirring speed 2000 r/mim to increase the melt viscosity, and then adding a few TiH2（0.02%） into the melt and stirring the melt for 6 min with stirring speed 2000 r/min. AlSi12 alloy foams with uniform cell structure, average pore diameter 2.4 mm and porosity 83.7% are obtained by the vacuum foaming processing as follows： foaming the melt for 10 s with vacuum degree of 5 Pa, and cooling the melt foams for 6 min in vacuum surroundings. The bubble nucleation of the initial pores in the AlSi12 alloy melt is heterogeneous nucleation, and these phases such as Si C, Al2O3 and SiO2, act as the nuclei of the heterogeneous nucleation.

关 键 词：AlSi12合金泡沫 初始气孔 真空发泡 工艺 

分 类 号：TG146.21[一般工业技术—材料科学与工程]