摘要
The interfacial oxidation behavior of Cr_(4)Mo_(4) V high-speed steel(HSS)joints undergoing hot-compression bonding was investigated by using optical microscopy(OM),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).In the heating and holding processes,dispersed rod-like and granularδ-Al_(2)O_(3) oxides were formed at the interface and in the matrix near the interface due to the selective oxidation and internal oxidation of Al,while irregular Si-Al-O compounds and spheroidal SiO_(2) particles were formed at the interface.After the post-holding treatment,SiO_(2) oxides and Si-Al-O compounds were dissolved into the matrix,andδ-Al_(2)O_(3) oxides were transformed into nanoscaleα-Al_(2)O_(3) particles,which did not deteriorate the mechanical properties of the joints.The formation and migration of newly-formed grain boundaries by plastic deformation and post-holding treatment were the main mechanism for interface healing.The tensile test results showed that the strength of the healed joints was comparable to that of the base material,and the in-situ tensile observations proved that the fracture was initiated at the grain boundary of the matrix rather than at the interface.The clarification of interfacial oxides and microstructure is essential for the application of hot-compression bonding of HSSs.
基金
financially supported by the National Key Research and Development Program(No.2018YFA0702900)
the National Natural Science Foundation of China(Nos.51774265 and 51701225)
the National Science and Technology Major Project of China(Nos.2019ZX06004010 and 2017-VII008-0101)
the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDC04000000)
the LingChuang Research Project of China National Nuclear Corporation Program of CAS Interdisciplinary Innovation Team
Youth Innovation Promotion Association,CAS。
