高强铝合金特厚板的真空轧制复合制备技术

Vacuum Rolling Cladding Technology for Heavy Thick High-Strength Al Alloy Plate

为解决高强铝合金特厚板的心部偏析、疏松、气孔等问题,提出了一种高强铝合金特厚板的制备方法,即基于真空搅拌摩擦焊的热轧复合技术.该技术的流程包括:铝合金坯料表面清理、利用自主研发的真空搅拌摩擦焊机进行坯料封装及复合坯料的热轧和热处理.在0.01 Pa真空度下对7050高强铝合金进行焊接封装,然后在450℃和75%总压下率下进行轧制复合,最后对复合板进行固溶+时效处理.分析发现,复合界面无任何裂纹、气孔等缺陷,原始界面消失,两侧金属融为一体,界面仅分布少量细小的MgO颗粒.界面剪切强度达266 MPa,达到基材的99%,界面实现了优异的冶金结合.

In order to improve the segregation,loose,and porosity in the center region of heavy thick high-strength Al alloy plate,a rolling cladding technique was developed based on vacuum friction stir welding(FSW).The process included the surface treatment,vacuum FSW,hot-roll cladding,and heat treatment.The 7050-Al alloy blanks were welded by FSW at 0.01 Pa,and then were cladding by hot rolling at 450℃with the total reduction ratio of 75%.Subsequently,the cladding plate was subjected to the solid-solution and aging heat treatments.No any crack or porosity was observed at the cladding interface,and the original cladding interface disappeared,only remaining a few of fine and dispersed MgO particles on it.The shear strength of the cladding interface is up to 266 MPa,which reaches 99%of the substrate strength,so that an excellent metallurgical bonded interface is obtained.