scholarly journals Virtual Development of Process Parameters for Bulk Metallic Glass Formation in Laser-Based Powder Bed Fusion

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 450
Author(s):  
Johan Lindwall ◽  
Andreas Lundbäck ◽  
Jithin James Marattukalam ◽  
Anders Ericsson
Keyword(s):  
Additive Manufacturing ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Process Parameters ◽  
Glass Formation ◽  
Laser Power ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Scanning Strategies ◽  
Hatch Spacing

The development of process parameters and scanning strategies for bulk metallic glass formation during additive manufacturing is time-consuming and costly. It typically involves trials with varying settings and destructive testing to evaluate the final phase structure of the experimental samples. In this study, we present an alternative method by modelling to predict the influence of the process parameters on the crystalline phase evolution during laser-based powder bed fusion (PBF-LB). The methodology is demonstrated by performing simulations, varying the following parameters: laser power, hatch spacing and hatch length. The results are compared in terms of crystalline volume fraction, crystal number density and mean crystal radius after scanning five consecutive layers. The result from the simulation shows an identical trend for the predicted crystalline phase fraction compared to the experimental estimates. It is shown that a low laser power, large hatch spacing and long hatch lengths are beneficial for glass formation during PBF-LB. The absolute values show an offset though, over-predicted by the numerical model. The method can indicate favourable parameter settings and be a complementary tool in the development of scanning strategies and processing parameters for additive manufacturing of bulk metallic glass.

Thermal simulation and phase modeling of bulk metallic glass in the powder bed fusion process

2019 ◽  
Vol 27 ◽  
pp. 345-352 ◽  
Author(s):  
Johan Lindwall ◽  
Victor Pacheco ◽  
Martin Sahlberg ◽  
Andreas Lundbäck ◽  
Lars-Erik Lindgren
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Thermal Simulation ◽  
Fusion Process ◽  
Powder Bed Fusion ◽  
Powder Bed

Quasicrystalline Composites by Additive Manufacturing

2019 ◽  
Vol 818 ◽  
pp. 72-76 ◽  
Author(s):  
Konda Gokuldoss Prashanth ◽  
Sergio Scudino
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Complex Shape ◽  
Powder Bed Fusion ◽  
Laser Melting ◽  
Powder Bed ◽  
Novel Materials ◽  
Tunable Properties

Laser based powder bed fusion (LBPF) or selective laser melting (SLM) is making a leap march towards fabricating novel materials with improved functionalities. An attempt has been made here to fabricate hard quasicrystalline composites via SLM, which demonstrates that the process parameters can be used to vary the phases in the composites. The mechanical properties of the composite depend on their constituents and hence can be varied by varying the process parameters. The results show that SLM not only produces parts with improved functionalities and complex shape but also leads to defined phases and tunable properties.

Effect of hatch spacing and laser power on microstructure, texture, and thermomechanical properties of laser powder bed fusion (L-PBF) additively manufactured NiTi

2021 ◽  
pp. 107680
Author(s):  
Sayed Ehsan Saghaian ◽  
Mohammadreza Nematollahi ◽  
Guher Toker ◽  
Alejandro Hinojos ◽  
Narges Shayesteh Moghaddam ◽  
...  
Keyword(s):  
Laser Power ◽  
Thermomechanical Properties ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Hatch Spacing

Optimization of parameters for SLS of WC-Co

2017 ◽  
Vol 23 (6) ◽  
pp. 1202-1211 ◽  
Author(s):  
Sanjay Kumar ◽  
Aleksander Czekanski
Keyword(s):  
Energy Density ◽  
Process Parameters ◽  
Laser Power ◽  
Laser Energy ◽  
Beam Diameter ◽  
Content Type ◽  
Powder Bed ◽  
Scan Speed ◽  
New Equation ◽  
Hatch Spacing

Purpose WC-Co is a well-known material for conventional tooling but is not yet commercially available for additive manufacturing. Processing it by selective laser sintering (SLS) will pave the way for its commercialization and adoption. Design/methodology/approach It is intended to optimize process parameters (laser power, hatch spacing, scan speed) by fabricating a bigger part (minimum size of 10 mm diameter and 5 mm height). Microstructural analysis, EDX and hardness testing is used to study effects of process parameters. Optimized parameter is ascertained after fabricating 49 samples in preliminary experiment, 27 samples in pre-final experiment and 9 samples in final experiment. Findings Higher laser power gives rise to cracks and depletion of cobalt while higher scan speed increases porosity. Higher hatch spacing is responsible for delamination and displacement of parts. Optimized parameters are 270 W laser power, 500 mm/s scan speed, 0.04 mm layer thickness, 0.04 mm hatch spacing (resulting in energy density of 216 J/mm3) and 200°C powder bed temperature. A part comprising of small hole of 2 mm diameter, thin cylindrical pin of 0.5 mm diameter and thin wall of 2 mm width bent up to 30° angle to the base plate is fabricated. In order to calculate laser energy density, a new equation is introduced which takes into account both beam diameter and hatch spacing unlike old equation does. In order to calculate laser energy density, a new equation is formulated which takes into account both beam diameter and hatch spacing unlike old equation does. WC was not completely melted as intended giving rise to partial melting-type binding mechanism. This justified the name SLS for process in place of SLM (Selective Laser Melting). Research limitations/implications Using all possible combination of parameters plus heating the part bed to maximum shows limitation of state-of-the-art commercial powder bed fusion machine for shaping hardmetal consisting of high amount of WC (83 wt. per cent). Practical implications The research shows that microfeatures could be fabricated using WC-Co which will herald renewed interest in investigating hardmetals using SLS for manufacturing complex hard tools, molds and wear-resistance parts. Originality/value This is the first time micro features are successfully fabricated using WC-Co without post-processing (infiltration, machining) and without the help of additional binding material (such as Cu, Ni, Fe).

3D pore structure characterization and hardness in a powder bed fusion-processed fully amorphous Zr-based bulk metallic glass

2020 ◽  
Vol 162 ◽  
pp. 110178 ◽  
Author(s):  
Jianye Shi ◽  
Songyun Ma ◽  
Shuai Wei ◽  
James P. Best ◽  
Moritz Stolpe ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Pore Structure ◽  
Bulk Metallic Glass ◽  
Structure Characterization ◽  
Powder Bed Fusion ◽  
Powder Bed

scholarly journals Understanding Laser Powder Bed Fusion Surface Roughness

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Jacob C. Snyder ◽  
Karen A. Thole
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Comprehensive Understanding ◽  
Powder Bed ◽  
Manufacturing Methods ◽  
New Framework

Abstract Surface roughness is a well-known consequence of additive manufacturing methods, particularly powder bed fusion processes. To properly design parts for additive manufacturing, a comprehensive understanding of the inherent roughness is necessary. While many researchers have measured different surface roughness resultant from a variety of parameters in the laser powder bed fusion process, few have succeeded in determining causal relationships due to the large number of variables at play. To assist the community in understanding the roughness in laser powder bed fusion processes, this study explored several studies from the literature to identify common trends and discrepancies amongst roughness data. Then, an experimental study was carried out to explore the influence of certain process parameters on surface roughness. Through these comparisons, certain local and global roughness trends have been identified and discussed, as well as a new framework for considering the effect of process parameters on surface roughness.

Bimetal printing of high entropy alloy/metallic glass by laser powder bed fusion additive manufacturing

2022 ◽  
Vol 141 ◽  
pp. 107430
Author(s):  
Hao Wang ◽  
Junquan Chen ◽  
Hailu Luo ◽  
Di Wang ◽  
Changhui Song ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Metallic Glass ◽  
High Entropy Alloy ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
High Entropy

scholarly journals Laser Powder Bed Fusion of Pure Tungsten: Effects of Process Parameters on Morphology, Densification, Microstructure

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 165
Author(s):  
Junfeng Li ◽  
Yunxiao Wu ◽  
Bokang Zhou ◽  
Zhengying Wei
Keyword(s):  
Relative Density ◽  
Laser Power ◽  
Grain Morphology ◽  
Scanning Speed ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
High Laser ◽  
Columnar Grains ◽  
Hatch Spacing

Tungsten has been widely used in many industrial fields due to its excellent properties. However, owing to its characteristics of inherent brittleness at room temperature and high melting point, it is difficult to prepare tungsten parts with high complexity via traditional methods. In the present work, tungsten samples were prepared by laser powder bed fusion. The influence of each process parameter including laser power, scanning speed, and hatch spacing on the surface morphology, densification, and microstructure of tungsten samples was systematically investigated. The results showed that the use of the appropriate parameters, especially high laser power, can effectively improve the surface quality and obtain a dense surface. The tungsten samples with a relative density of 98.31% were obtained with optimized parameter combinations: a laser power of 300 W, scanning speed of 400 mm/s, and hatch spacing of 0.08 mm. Compared with scanning speed and hatch spacing, the laser power had a more obvious influence on the relative density. Additionally, for the grain morphology by microstructure inspection, elongated curved grains gradually transformed into fine straight columnar grains as the scanning speed increased. The hatch spacing would change the grain morphology slightly but had no significant effect on the grain size.

Sign in / Sign up

Export Citation Format

Share Document