Abstract
As a prospective candidate material for surface coating and repair applications, nickel-based superalloy Inconel 718 (IN718) was deposited on American Iron and Steel Institute (AISI) 4140 alloy steel substrate by laser engineered net shaping (LENS) to investigate the compatibility between two dissimilar materials with a focus on interface bonding and fracture behavior of the hybrid specimens. The results show that the interface between the two dissimilar materials exhibits good metallurgical bonding. Through the tensile test, all the fractures occurred in the as-deposited IN718 section rather than the interface or the substrate, implying that the as-deposited interlayer bond strength is weaker than the interfacial bond strength. From the fractography using scanning electron microscopy (SEM) and energy disperse X-ray spectrometry (EDS), three major factors affecting the tensile fracture failure of the as-deposited part are (i) metallurgical defects such as incompletely melted powder particles, lack-of-fusion porosity, and micropores; (ii) elemental segregation and Laves phase, and (iii) oxide formation. The fracture failure mechanism is a combination of all these factors which are detrimental to the mechanical properties and structural integrity by causing premature fracture failure of the as-deposited IN718.
Highlights
American Iron and Steel Institute (AISI) 4140 alloy steel has been widely used for the manufacturing of gear components due to its good performance of strength, toughness, and wear resistance [1]
When they are exposed to harsh working environments such as high temperature, high speed sliding contact, and frictional heat generation, their surfaces undergo severe damage such as micropitting of gear teeth flanks and tooth breakage in the tooth root due to repeated cyclic sliding loading under long-term service, which is detrimental to the service life of the critical gear components and leads to the complete failure of the gear [3,4]
4140 substrate and the as‐deposited Inconel 718 (IN718) obtained from the hybrid tensile specimen
Summary
Due to the harsh working conditions of the components made of this alloy steel, it is necessary to extend their service life and refurbish the worn or damaged parts [2] When they are exposed to harsh working environments such as high temperature, high speed sliding contact, and frictional heat generation, their surfaces undergo severe damage such as micropitting of gear teeth flanks and tooth breakage in the tooth root due to repeated cyclic sliding loading under long-term service, which is detrimental to the service life of the critical gear components and leads to the complete failure of the gear [3,4]. There exists a high demand in industry to improve the performance and durability
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
