采用LMC高梯度定向凝固和微观分析方法,研究了不同凝固速率下IN718合金的凝固组织和偏析行为.结果表明,随着凝固速率的提高,凝固界面由胞晶转为枝晶;一次胞/枝晶间距在凝固速率为20μm/s时提高到最大值257μm,随后逐渐降低,二次枝晶间距明显细化,溶质分配比也随凝固速率的增加而减小.同时,凝固速率增加使糊状区枝晶骨架的渗透性减小,增大了对液体流动的阻碍作用.
参考文献
| [1] | C.Malara,J.Radavich,Alloy 718 Large Ingots Studies,in:Superalloys 718.625.706 and Various Derivatives,E.A.Loria ed.,(Pittsburgh,PA:TMS,USA,2005)p.25 |
| [2] | S.M.Copley,A.F.Giamei,S.M.Johnson,M.F.Hornbecker,The origin of freckles in unidirectionally solidified casting,Metallurgical Transactions,1,2193(1970) |
| [3] | W.H.Yang,Keh-Minn Chang,Wei Chen,Sarwan Mannan,John DeBarbadillo,Freckle criteria for the upward directional solidification of alloys,Metallurgical and Materieds Transactions A,.32(2),397(2001) |
| [4] | P.Auburtin,S.L.Cockcroft,A.Mitchell,Liquid density inversion during the solidification of superalloys and their relationship tof reckle,formation in castings,in:Superalloys,R.D.Kissmger,et al.ed.,(Warrendale,PA:TMS,USA,1996)p.443 |
| [5] | J.C.Heinrich,D.R.Poirier,Convection modeling in directional solidification,Comptes Rendus Mecanique,332(5-6),429(2004) |
| [6] | D.R.Poirier,S.Ganesan,Permeabilities for flow of interdendritic liquid in equiaxiai structures,Materials Science and Engineering:A,157(1),113(1992) |
| [7] | YU Yongning.Fundamentals of materials science and engeering,(Beijing,Metallurgical Industry Press,2003)P.252-257(余永宁[编],金属学原理,(北京,冶金工业出版社,2003)p.252-257) |
| [8] | LIU Zhongyuan,LI Jianguo,FU Hengzhi,Dendritic arm spacing and micrcosegregation of directionally solidified superalloy DZ22 at various solidification rates,Acta Metallurgica Sinica,31(7),229(1995)(刘忠元,李建国,傅恒志,凝固速率对定向凝固合金DZ22枝晶臂间距和枝晶偏析的影响,金属学报,31(7),229(1995)) |
| [9] | A.D.Patel,V.Y.Murty,Effect of Cooling Rate on Microstructural Development,in:Alloy 718.Superalloys 718.625.706 and Various Derivatives,E.A.Loria ed.,(Warrendale,PA:TMS,USA,2001)p.123 |
| [10] | R.G.Santos,M.L.N.M.Melo.Permeability of interdendritic channels,Materials Science and Engineering A,391(1-2),151(2005) |
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