耐热低膨胀高硅铝合金的成形与性能.pdfVIP

学兔兔 铸 造 Feb．2010 ·134· FOUNDRY VOI：59 NO．2 耐热低膨胀高硅铝合金的成形与性能 吴树森，钟 鼓，姜华文，万 里，安 萍，毛有武 (华中科技大学材料成形与模具技术国家重点实验室，湖北武汉430074) 摘要：利用超声振动半固态流变压铸成形的方法制备出含20％Si的A1SiCuMgNiRE合金，研究了这种合金的组织、高 温性能及热膨胀性能。结果表明，P与稀土复合变质的高硅铝合金，300℃的高温抗拉强度达到167 MPa，室温强度达 到310 MPa；25～300℃内的热膨胀系数为17．4x10 (1／℃)。添~2％Fe的高硅铝合金，由于针状富Fe相割裂基体，力学 性能大幅度降低。而通过超声处理可改变富Fe相的形态，其室温及高温力学性能提高。 关键词：高硅铝合金；高温性能；显微组织；变质；热膨胀 中图分类号：TG146．2 1 文献标识码：A 文章编号：100l一4977(2010)02—0134—04 Formation and Properties of Low Expansive and Heat—Resistant AlUminUm Alloy with High Silicon Content WU Shu-sen，ZHONG Gu，JIANG Hua—wen，WAN Li，AN Ping，MAO You-wu (State Key Laboratory of Materials Processing and Moulds＆Dies Technology，Huazhong University of Science and Technology，Wuhan 430074，Hubei，China) Abstract： An AlSiCuMgNiRE aluminum alloy with 2O％ Sj was fabricated by semi．solid rheo．diecasting method。jn which slurry was made with ultrasonic vibration．and the microstructure， mechanicaI properties at high temperature and thermaI expansion of this alloy were studied．The results show that．if it iS complex modified with P and RE，the high temperature tensile strength at 300℃ of this high Si aIuminum alloy reaches 1 67 MPa．the tensile strength at room temperature iS about 310 MPa，and the thermaI expansion coe仟icient from 25℃to 300℃iS 17．4xlO．6(1，℃)． When 2％Fe was added．the mechanicaI properties were greatly decreased because of the cu~ing effect of needle．shape Fe．containing compound on the matrix．However，the tensile strengths at room and high temperatures