Influence of selective laser melting process parameters on the surface integrity of difficult-to-cut alloys: comprehensive review and future prospects

Abstract

Difficult-to-cut alloys, which include titanium, cobalt, nickel alloys, and high-strength and heat-resistant steels, can nowadays be manufactured using selective melting (SLM), and products made of such materials are widely used in aerospace, automotive, and medical applications. SLM is widely used among other methods of additive manufacturing (AM) for the production of parts with complex geometry which are difficult to produce using conventional manufacturing processes. In this review article, for the first time, a comprehensive literature review of the most important parameters which influence the SLM manufacturing process of difficult-to-cut alloys is discussed and analysed. Parameters such as composition, grain size, defects, texture, and thermo-mechanical properties and their effect on surface integrity, namely surface topography (machined surface defects, surface roughness, surface texture), microstructural alterations (plastic deformation, grain refinement, and orientation, white layer formation), and mechanical properties (work hardening layer formation and microhardness, residual stress) are discussed. As a result, this review article shows the advantages and disadvantages of using various compositions, classifications, microstructure, defects, and properties of SLM of difficult-to-cut alloys on surface integrity and outlines development prospects, challenges, and future trends.

A Review on Vibration Characteristics of Additively Manufactured Metal Alloys

“…As the VA mainly uses the density and Young's modulus values of the AM metal alloys, the porosity and cracking through the surface can be more susceptible to failure of AM parts by vibrations. [33,34] Similarly, because of process parameters, there are various defects like lack of fusion, [35] balling, [36] and keyhole depression, [37] which can also contribute to the changes in the mechanical properties of AM parts. [34] The defect mainly affects the tensile properties and density of the AM metal alloys; the more the porosity of the AM metal alloys, the more the density will reduce, which can change the natural frequencies of the AM parts.…”

Impact of process parameters on the dynamic behavior of Inconel 718 fabricated via laser powder bed fusion

“…Several studies [15][16][17][18][19][20][21][22] characterized the influence of the process parameters adopted during the printing process on the bulk (Young modulus, yield and tensile strength, ductility, elongation at break, porosity) and surface (fatigue strength, surface roughness) properties of the material. Considering the widely used L-PBF process, the features of the metal powder used, the parameters of the laser beam, and the heat treatments undergone by the material are the most influencing factors for the final properties of the printed component [23][24][25][26][27]. Adopting a different scanning strategy, printing direction, layer thickness, hatch distance, and energy density produces different surface textures, microstructures, and mechanical properties of the material [28][29][30][31][32][33][34][35][36][37].…”