C.Z. Chen1
,
2)
,
T.Q. Lei2)
,
D.W. Cui1)and J.H. Yu1) 1) College of MaterialScience and Technology
,
Shandong University of Technology
,
Jinan 250061
,
China2) College of MaterialScience and Technology
,
Harbin Institute of Technology
,
Harbin 150001
,
China
金属学报(英文版)
The microstructure and formation mechanism of laser clad Ni60 Acoating were studied by meansof XRD, SEM, TEMand EDAXetc. Theresultsshow thatthe microstructureofthe coatingiscontrolled bytheratiooftemperature gradient Gand solidification speed υ( G/υ)atthesolid liquidinterface. Attheinterfaceof molten pool/substrate, G/υisquitelarge,and Ni basedsolid solutionsgrowingintheform oflow speed planar grain boundary form abonding belt. With the advancement of the solid liquid interface, G/υdecreases, and a bonding zone mainly composed ofcomplex cellulareutecticsof Ni+ M23( CB)6 and Ni+ Ni3Bisformed when G/υisstilllargeenough. Further decrease willlead to a clad layerthat exhibitscellular and dendritic Ni basedsolidsolutions,dendriticor discontinuousnetwork M7( CB)3 and complex eutectics( Ni+ M23( CB)6 and Ni+ Ni3 B) between them .
关键词:
microstructure
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