[1] McCandlish L E, Kear B H, Bhatia S J. World Pat WO91/07244, 1991 [2] Zhang L Y, Wu C Y. In: Japan Technology Association ed.,The 1st China and Japanese Technology Information Com-munite Siminar. Kynshu City, Japan: Japan Kyushu Insti-tute of Technology, 1996: 12 [3] Zhans L Y, wu C Y. Chin Pat 971220859, 1997(张丽英,吴成义.中国专利971220859, 1997) [4] Zhang L Y, Wu C Y. In: Japan Powder Metallurgy Associa-tion ed., Powder Metallugy World Congress, Kyoto Japan,1993: 538 [5] Zhang L Y, Wu C Y. Chin Pat ZL94247337X, 1994 [6] (张丽英,吴成义 中国专利ZL94247337X, 1994)