Microstructural and mechanical evaluation of ۱۵-۵PH SS/BNi-۳/۱۵-۵PHSS bonded by TLP process

In the present study, Transient Liquid Phase (TLP) bonding of۱۵-۵PH stainless steel wascarried out by using BNi-۳ interlayer. The bonding process was carried out at ۱۱۵۰oC for۵min and ۳۰min under protection of ۹۹.۹۹۵% Ar shielding gas. The microstructuralinvestigations of the bonding area was carried by using optical and scanning electronmicroscopes equipped to EDS analyzer. Cooling the samples before the completion ofthermal solidification causes non-isothermal solidification of the remaining melt in thecentral line of bonding zone and the formation of boride compounds. Microstructuralstudies showed that increasing the joining time from ۵min to ۳۰min results in completionof isothermal solidification and the formation ofa uniform nickel-rich solid solution in atthe bonding zone. The continuous morphology of the eutectic compounds formed duringnon-isothermal solidification caused a sharp drop in the shear strength of the bondedspecimens. Applying thermal aging treatment after joining led to modification of the sizeof martensite laths and uniformity hardness in the joint area.

کلیدواژه ها:

TLP Bonding ، ۱۵-۵PH Steel ، Aging Heat Treatment ، Microstructure ، Microhardness.