Abstract：The microstructures of in-situ reactive liquidus cast 7075+X%(volume fraction)TiC((X=0,0.5,1.2,2.5))Al alloys at semi-solid state were observed using SEM.The grain sizes were measured using a mean linear intercept method and the effect of in-situ TiC particles on grain growth in the two-phase(liquid+solid)region of liquidus cast 7075 Al alloy was analyzed.The result shows that the in-situ TiC particles can not only keep liquidus cast 7075 Al alloy with fine and globular microstructure,but also control evidently grains growth by pinning effect during reheating.
[1] 谢水生,黄声宏.半固态金属加工技术及其应用[M].北京:冶金工业出版社,1999. [2] ERRIQUE J,LAVERNIA,YUE WU.Spray atomization and deposition[M].New York:John Wiley and Sons,1996.338-345. [3] 路贵民,董杰,崔建忠,等.7075铝合金液相线半连续铸造组织及形成机理[J].金属学报,2001,37(10):1045-1051. [4] FERRANTE M,FREITAS EDE.Rheology and microstructural development of a Al-4% Cu alloy in the semi-solid state[J].Materials Science and Engineering,1999,A271:172-178. [5] GEBELIN J C,SUERY M,FAVIER D.Characterisation of the rheological behaviour in the semi-solid state of grain-refined AZ91 magnesium alloys[J].Materials Science and Engineering,1999,A272:134-141. [6] ZOQUI E J,SHEHATAM T,AES M P,et al.Morphological evolution of SSMA356 during partial remelting[J].Materials Science and Engineering,2002,A325:38-42. [7] LAWRYNOWICZ D E,WOLFENSTINE J,LAVERNIA E J.Grain growth mechanisms in a sprayformed Ni3Al/Al2O3 com posite in the presence of a liquid phase[J].Materials Science and Engineering,1997,A230:1-12. [8] WANG J L,SU Y H,TSAO C-Y A.Structural evolution of conventional cast dendritic and spray-cast non-dendritic structures during isothermal holding in the semi-solid state[J].Scripta Materialia,1997,37(12):2003--2012. [9] MANSON-WHITTON E D,STONE I C,JONES J R,et al.Isothermal grain coarsening of spray formed alloy in the semi-solid state[J].Acta Materialia,2002,50:2517-2524. [10] XIA K,TAUSING G.Liquidus casting of a wrought aluminum alloy 2518 for thixoforming[J].Materials Science and Engineering,1998,A246:1-9. [11] 刘慧敏,王洪斌,杨滨,等.原位TiC颗粒对喷射成形7075合金组织的影响[J].北京科技大学学报,2003,25:337-341. [12] LIU Hui-min,CUI Hua,YANG Bin,et al.Isothermal grain growth of reactive sprayformed 7075 alloys in the semi-solid state[J].Journal of University of Science and Technology Beijing,2004,11(5):411-414. [13] 武恭,姚良均,李震霞,等.铝及铝合金材料手册[M].北京:科学出版社,1997.255-256.
2006, Vol. 
