8Huang Liangyu. Skeleton description of grain refinement of alumi- num and aluminium alloy [ J ]. Special Casting and Nonferrous Al- loys, 1997,(3) : 41 -43.
9Jiang Xinggang, Cui Jianzhong. Grain refinement and super plas- ticity of high strength 7475 aluminium alloy[ J]. Materials Science and Technology, 1993, 9(5) : 493 -496.