Selective laser melting of stainless steel 316L with low porosity and high build rates

This study aimed to investigate the stainless steel 316L processing by means of selective laser melting (SLM). The processing parameters under consideration included laser power (25-225 W), scanning speed (50-320 mm/s), and scan spacing (0.04 and 0.06 mm). Every processing was constrained the layer thickness as of 100 µm. All parameters were performed based on two experiments, line scanning and multiple layers scanning. Each of final workpieces was examined by visual inspection, density measurement, hardness, and built rate. From the experiments, the optimal processing conditions which produced the smooth tracks were obtained. The workpiece processed by this optimal processing condition presented quality characteristics with 97.6% density and 220±6 HV hardness.

Download Full-text

Metallic Materials Prepared by Selective Laser Melting: Part Orientation Issue

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.779.165 ◽

2018 ◽

Vol 779 ◽

pp. 165-173

Author(s):

Michaela Fousova ◽

Drahomír Dvorský ◽

Pavel Lejček ◽

Dalibor Vojtěch

Keyword(s):

Mechanical Properties ◽

Stainless Steel ◽

Selective Laser Melting ◽

Metallic Materials ◽

Stainless Steel 316L ◽

Laser Melting ◽

Individual Effects ◽

Oriented Samples ◽

Part Orientation ◽

Melting Part

This paper shows part orientation issue in the process of Selective Laser Melting (SLM) at four examples of metallic materials (Fe, stainless steel 316L, TiAl6V4 alloy and AlSi11Mg alloy). Horizontally and vertically oriented samples differ in their mechanical properties, especially in plasticity. The causes of these differences are related to a thermal history, microstructural features and porosity. Depending on a particular material, individual effects are manifested under different extents.

Download Full-text

Evaluation of residual stress in stainless steel 316L and Ti6Al4V samples produced by selective laser melting

Virtual and Physical Prototyping ◽

10.1080/17452759.2015.1026045 ◽

2015 ◽

Vol 10 (2) ◽

pp. 67-76 ◽

Cited By ~ 132

Author(s):

Igor Yadroitsev ◽

Ina Yadroitsava

Keyword(s):

Residual Stress ◽

Stainless Steel ◽

Selective Laser Melting ◽

Stainless Steel 316L ◽

Laser Melting

Download Full-text

Influences of Horizontal and Vertical Build Orientations and Post-Fabrication Processes on the Fatigue Behavior of Stainless Steel 316L Produced by Selective Laser Melting

Materials ◽

10.3390/ma12244203 ◽

2019 ◽

Vol 12 (24) ◽

pp. 4203 ◽

Cited By ~ 3

Author(s):

Paul Wood ◽

Tomasz Libura ◽

Zbigniew L. Kowalewski ◽

Gavin Williams ◽

Ahmad Serjouei

Keyword(s):

Stainless Steel ◽

Selective Laser Melting ◽

Shot Peening ◽

Fatigue Behavior ◽

Fracture Pattern ◽

Fatigue Properties ◽

Stainless Steel 316L ◽

Laser Melting ◽

Test Pieces ◽

Laser Systems

In this paper, the influences of build orientation and post-fabrication processes, including stress-relief, machining, and shot-peening, on the fatigue behavior of stainless steel (SS) 316L manufactured using selective laser melting (SLM) are studied. It was found that horizontally-built (XY) and machined (M) test pieces, which had not been previously studied in the literature, in both stress-relieved (SR) or non-stress-relieved (NSR) conditions show superior fatigue behavior compared to vertically-built (ZX) and conventionally-manufactured SS 316L. The XY, M, and SR (XY-M-SR) test pieces displayed fatigue behavior similar to the XY-M-NSR test pieces, implying that SR does not have a considerable effect on the fatigue behavior of XY and M test pieces. ZX-M-SR test pieces, due to their considerably lower ductility, exhibited significantly larger scatter and a lower fatigue strength compared to ZX-M-NSR samples. Shot-peening (SP) displayed a positive effect on improving the fatigue behavior of the ZX-NSR test pieces due to a compressive stress of 58 MPa induced on the surface of the test pieces. Fractography of the tensile and fatigue test pieces revealed a deeper understanding of the relationships between the process parameters, microstructure, and mechanical properties for SS 316L produced by laser systems. For example, fish-eye fracture pattern or spherical stair features were not previously observed or explained for cyclically-loaded SLM-printed parts in the literature. This study provides comprehensive insight into the anisotropy of the static and fatigue properties of SLM-printed parts, as well as the pre- and post-fabrication parameters that can be employed to improve the fatigue behavior of steel alloys manufactured using laser systems.

Download Full-text

Finite Element Analysis to Improve the Accuracy of Parts Made by Stainless Steel 316L Material Using Selective Laser Melting Technology

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.657.236 ◽

2014 ◽

Vol 657 ◽

pp. 236-240 ◽

Cited By ~ 2

Author(s):

Razvan Păcurar ◽

Ancuţa Păcurar

Keyword(s):

Finite Element ◽

Stainless Steel ◽

Selective Laser Melting ◽

Thermal Stresses ◽

Melting Process ◽

Optimum Process ◽

Stainless Steel 316L ◽

Laser Melting ◽

Element Analysis ◽

Bed Temperature

One of the serious problems in the SLM process, using metallic powders is the thermal distortion of the model during forming. As a result of the locally concentrated energy input, the temperature gradient mechanism and the related processes lead to residual stresses and part deformations. Since the solidified part is cooled rapidly, the model tends to be deformed and cracked due to the thermal stresses. All these aspects were considered for a series of analyses that were made using the finite element method in order to determine the optimum process parameters (laser power, scanning speed, powder bed temperature) that are required in order to improve the accuracy of the metallic parts made by Stainless Steel 316L material using the Selective Laser Melting process.

Download Full-text