A Comparative Analysis of Laser Additive Manufacturing of High Layer Thickness Pure Ti and Inconel 718 Alloy Materials Using Finite Element Method

Abstract

Investigation of the selective laser melting (SLM) process, using finite element method, to understand the influences of laser power and scanning speed on the heat flow and melt-pool dimensions is a challenging task. Most of the existing studies are focused on the study of thin layer thickness and comparative study of same materials under different manufacturing conditions. The present work is focused on comparative analysis of thermal cycles and complex melt-pool behavior of a high layer thickness multi-layer laser additive manufacturing (LAM) of pure Titanium (Ti) and Inconel 718. A transient 3D finite-element model is developed to perform a quantitative comparative study on two materials to examine the temperature distribution and disparities in melt-pool behaviours under similar processing conditions. It is observed that the layers are properly melted and sintered for the considered process parameters. The temperature and melt-pool increases as laser power move in the same layer and when new layers are added. The same is observed when the laser power increases, and opposite is observed for increasing scanning speed while keeping other parameters constant. It is also found that Inconel 718 alloy has a higher maximum temperature than Ti material for the same process parameter and hence higher melt-pool dimensions.

Thermal design considerations for a L-PBF built metal component: effects of Inter-Layer Cooling Time, Preheating Temperature and Gas Flow

“…The gas flow system, which provided the EOS machine, including all its components, is summarized in Figure 4. All the specimens were exposed with the following process parameters, widely developed in previous literature studies [46,47]: Laser Power 280W, Scanning Speed 1000 mm/s and Hatch Distance 0.10 mm.…”

“…This phenomenon is evaluated through two case studies using nickel-based superalloy Inconel 718 and investigating the effect on two layers thickness, respectively, of 40 and 60 microns. All the results are evaluated through the Melt Pool analysis [31][32][33][34] of several Single and Multi-Tracks [35][36][37][38]. More specifically, it will be investigated if the preheating temperature affects the Melt Pool shape and the Melting regime as a function of the substrate height of the tested specimen.…”

Advances and Challenges in Predictive Modeling for Additive Manufacturing of Dissimilar Metals and Complex Alloys

“…Predicting these effects employing quasi-static elastoplastic models prior to fabrication facilitates a reduction in the above-mentioned artifacts to achieve a high-quality part [ 2 , 28 , 141 ]. Quasi-static elastoplastic models in general constitute a twofold process and can be categorized into (a) coupled and (b) weakly/uncoupled methods [ 35 , 90 , 103 , 117 ]. A coupled analysis considers the effects of thermal expansion on the mechanical properties within the model, while the weakly coupled model assumes them to be independent and requires the user to serve as a middleman.…”

Study on the Effect of Inter-Layer Cooling Time on Porosity and Melt Pool in Inconel 718 Components Processed by Laser Powder Bed Fusion

“…Despite all these advantages compared to the conventional machining methods, this process is affected by low efficiency in terms of material handling, high maintenance costs and low production volume [13]. The build rate of L-PBF is roughly estimated to be around 40 cm 3 /h, lower than that estimated for electron beam melting (EBM) and direct energy deposition (DED) of 70-100 and 140 cm 3 /h, respectively [14].…”

“…The use of L-PBF can solve some of the manufacturing problems of these materials, which are difficult to manufacture using conventional machining methods due to their high hardness and low thermal conductivity. Despite all these advantages compared to the conventional machining methods, this process is affected by low efficiency in terms of material handling, high maintenance costs and low production volume [13]. The build rate of L-PBF is roughly estimated to be around 40 cm 3 /h, lower than that estimated for electron beam melting (EBM) and direct energy deposition (DED) of 70-100 and 140 cm 3 /h, respectively [14].…”