Influence of directional solidification variables on primary dendrite arm spacing of Ni-based superalloy DZ125  

作　　者：Zhang Weiguo Liu Lin Huang Taiwen Zhao Xinbao Qu Min Yu Zhuhuan Fu Hengzhi 

机构地区：[1]State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi＇an 710072, China

出　　处：《China Foundry》2009年第4期300-304,共5页中国铸造（英文版）

基　　金：supported by the National Natural Science Foundation of China(50771081,50827102);the National Basic Research Program of China(2006CB605202)

摘　　要：The primary dendrite morphology and spacing of DZ125 superalloy have been observed during directional solidification under high thermal gradient about 500 K/cm. The results reveal that the primary dendrite arm spacing decreases from 94 μm to 35.8 μm with the increase of directional solidification cooling rate from 2.525 K/s to 36.4 K/s. The regression equation of the primary dendrite arm spacings A, versus cooling rate is λ1=0.013（GV）-0.32. The predictions of Kurz/Fisher model and Hunt/Lu model accord reasonably well with the experimental data. The influence of directional solidification rate under variable thermal gradient on the primary dendrite arm spacing has also been investigated.The primary dendrite morphology and spacing of DZ125 superalloy have been observed during directional solidification under high thermal gradient about 500 K/cm.The results reveal that the primary dendrite arm spacing decreases from 94μm to 35.8μm with the increase of directional solidification cooling rate from 2.525 K/s to 36.4 K/s.The regression equation of the primary dendrite arm spacingsλ 1 versus cooling rate is λ 1 =0.013(GV)-0.32.The predictions of Kurz/Fisher model and Hunt/Lu model accord reasonably well with the experimental data.The influence of directional solidi fication rate under variable thermal gradient on the primary dendrite arm spacing has also been investigated.

关 键 词：directional solidification thermal gradient cooling rate primary dendrite arm spacing SUPERALLOY 

分 类 号：TG146.15[一般工业技术—材料科学与工程] TF777[金属学及工艺—金属材料]