scholarly journals Effects of Different Substrates on the Formability and Densification Behaviors of Cemented Carbide Processed by Laser Powder Bed Fusion

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5027
Author(s):  
Decheng Liu ◽  
Wen Yue ◽  
Jiajie Kang ◽  
Chengbiao Wang
Keyword(s):  
Crack Formation ◽  
Laser Energy ◽  
Cutting Tools ◽  
Cemented Carbide ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Energy Inputs ◽  
High Laser Energy ◽  
Mold Fabrication

Cemented carbide materials are widely applied in cutting tools, drill tools, and mold fabrication due to their superior hardness and wear resistance. Producing cemented carbide parts via the laser powder bed fusion (L-PBF) method has the advantage of fabricating complex structures with a rapid manufacturing speed; however, they were underdeveloped due to their low density and crack formation on the blocks. This work studied the effect of different substrates including 316L substrates, Ni200 substrates, and YG15 substrates on the forming quality of WC-17Co parts fabricated by L-PBF, with the aim of finding the optimal substrate for fabrication. The results revealed that the Ni200 substrates had a better wettability for the single tracks formation than other substrates, and bonding between the built block and the Ni200 substrate was firm without separation during processing with a large range of laser energy inputs. This guaranteed the fabrication of a relatively dense block with fewer cracks. Although the high laser energy input that led to fine crack formation on the blocks formed on the Ni200 substrate, it was found to be better suited to restricting cracks than other substrates.

scholarly journals Laser Powder Bed Fusion Processing of Fe-Mn-Al-Ni Shape Memory Alloy—On the Effect of Elevated Platform Temperatures

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 185
Author(s):  
Felix Clemens Ewald ◽  
Florian Brenne ◽  
Tobias Gustmann ◽  
Malte Vollmer ◽  
Philipp Krooß ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Crack Formation ◽  
Microstructural Analysis ◽  
Tensile Load ◽  
Grain Structure ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Cyclic Heat Treatment ◽  
Powder Bed ◽  
Cyclic Heat

In order to overcome constraints related to crack formation during additive processing (laser powder bed fusion, L-BPF) of Fe-Mn-Al-Ni, the potential of high-temperature L-PBF processing was investigated in the present study. The effect of the process parameters on crack formation, grain structure, and phase distribution in the as-built condition, as well as in the course of cyclic heat treatment was examined by microstructural analysis. Optimized processing parameters were applied to fabricate cylindrical samples featuring a crack-free and columnar grained microstructure. In the course of cyclic heat treatment, abnormal grain growth (AGG) sets in, eventually promoting the evolution of a bamboo like microstructure. Testing under tensile load revealed a well-defined stress plateau and reversible strains of up to 4%.

scholarly journals Influence of Laser Energy Input and Shielding Gas Flow on Evaporation Fume during Laser Powder Bed Fusion of Zn Metal

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2677
Author(s):  
Yu Qin ◽  
Jinge Liu ◽  
Yanzhe Chen ◽  
Peng Wen ◽  
Yufeng Zheng ◽  
...  
Keyword(s):  
Energy Input ◽  
Gas Flow ◽  
Evaporation Rate ◽  
Laser Energy ◽  
Circulation System ◽  
Powder Bed Fusion ◽  
Shielding Gas ◽  
Laser Powder Bed Fusion ◽  
Conservation Of Energy ◽  
Powder Bed

Laser powder bed fusion (LPBF) of Zn-based metals exhibits prominent advantages to produce customized biodegradable implants. However, massive evaporation occurs during laser melting of Zn so that it becomes a critical issue to modulate laser energy input and gas shielding conditions to eliminate the negative effect of evaporation fume during the LPBF process. In this research, two numerical models were established to simulate the interaction between the scanning laser and Zn metal as well as the interaction between the shielding gas flow and the evaporation fume, respectively. The first model predicted the evaporation rate under different laser energy input by taking the effect of evaporation on the conservation of energy, momentum, and mass into consideration. With the evaporation rate as the input, the second model predicted the elimination effect of evaporation fume under different conditions of shielding gas flow by taking the effect of the gas circulation system including geometrical design and flow rate. In the case involving an adequate laser energy input and an optimized shielding gas flow, the evaporation fume was efficiently removed from the processing chamber during the LPBF process. Furthermore, the influence of evaporation on surface quality densification was discussed by comparing LPBF of pure Zn and a Titanium alloy. The established numerical analysis not only helps to find the adequate laser energy input and the optimized shielding gas flow for the LPBF of Zn based metal, but is also beneficial to understand the influence of evaporation on the LPBF process.

scholarly journals Formation Process of Microstructure in Laser Powder Bed Fusion with WC Cemented Carbide Powder

2020 ◽  
Vol 67 (6) ◽  
pp. 313-319
Author(s):  
Hiroyuki IBE ◽  
Yuta KATO ◽  
Jyunya YAMADA ◽  
Masaki KATO ◽  
Asuka SUZUKI ◽  
...  
Keyword(s):  
Formation Process ◽  
Cemented Carbide ◽  
Carbide Powder ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed

scholarly journals Effect of Laser Energy Density on the Microstructure andTexture Evolution of Hastelloy-X Alloy Fabricated by Laser Powder Bed Fusion

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4305
Author(s):  
Shuzhe Zhang ◽  
Yunpei Lei ◽  
Zhen Chen ◽  
Pei Wei ◽  
Wenjie Liu ◽  
...  
Keyword(s):  
Grain Size ◽  
Energy Density ◽  
Electron Backscatter Diffraction ◽  
Laser Energy ◽  
Primary Dendrite ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Hastelloy X ◽  
Powder Bed ◽  
Average Grain Size

It is of great importance to study the microstructure and textural evolution of laser powder bed fusion (LPBF) formed Hastelloy-X alloys, in order to establish a close relationship between the process, microstructure, and properties through the regulation of the Hastelloy-X formation process parameters. In this paper, components of a Hastelloy-X alloy were formed with different laser energy densities (also known as the volume energy density VED). The densification mechanism of Hastelloy-X was studied, and the causes of defects, such as pores and cracks, were analyzed. The influence of different energy densities on grain size, texture, and orientation was investigated using an electron backscatter diffraction technique. The results show that the average grain size, primary dendrite arm spacing, and number of low angle grain boundaries increased with the increase of energy density. At the same time, the VED can strengthen the texture. The textural intensity increases with the increase of energy density. The best mechanical properties were obtained at the VED of 96 J·mm−3.

Controlling crack formation and porosity in laser powder bed fusion: Alloy design and process optimisation

2020 ◽  
Vol 34 ◽  
pp. 101360 ◽  
Author(s):  
Hossein Eskandari Sabzi ◽  
Suhyun Maeng ◽  
Xingzhong Liang ◽  
Marco Simonelli ◽  
Nesma T. Aboulkhair ◽  
...  
Keyword(s):  
Crack Formation ◽  
Alloy Design ◽  
Powder Bed Fusion ◽  
Process Optimisation ◽  
Laser Powder Bed Fusion ◽  
Powder Bed

Investigation of mechanical properties and microstructures of GH536 fabricated by laser powder bed fusion additive manufacturing

2020 ◽  
Vol 235 (1-2) ◽  
pp. 155-165
Author(s):  
Yunpeng Ren ◽  
Heng Lu ◽  
Dongyang Xu ◽  
Yan Chen ◽  
Zhiduo Xin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Additive Manufacturing ◽  
Relative Density ◽  
Laser Energy ◽  
Hot Forging ◽  
Scanning Speed ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed

Laser powder bed fusion additive manufacturing of superalloys has received increasing attention in these years. In this article, the influence of parameters of laser powder bed fusion on mechanical properties and microstructures of nickel-based superalloy GH536 was investigated. Influence of laser power, scanning speed, hatch space and building direction on mechanical properties was discussed, and the optimal parameters were obtained. The relative density of samples fabricated by laser powder bed fusion could be as high as 99.5%. The processing window of laser energy density with 8.56 × 104–1.15 × 105 J/cm3 should be employed to make sure that the relative density is higher than 98%. The ultimate tensile strength and yield stress of GH536 sample made by laser powder bed fusion were 950 and 606 MPa, respectively, which were superior to samples with the tensile strength of 767 MPa and yield strength of 379 MPa prepared by traditional hot forging method. The hardness of the sample could reach 316.8 HV.

Forming feasibility and interface microstructure of Al/Cu bimetallic structure fabricated by laser powder bed fusion

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jieren Guan ◽  
Qiuping Wang ◽  
Chao Chen ◽  
Jingyu Xiao
Keyword(s):  
Laser Energy ◽  
Pure Copper ◽  
Diffusion Activation Energy ◽  
Interface Microstructure ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Heat Accumulation ◽  
Content Type ◽  
Temperature Changes ◽  
Powder Bed

Purpose The purpose of this paper is to analyze and investigate heat accumulation caused by temperature changes and interface microstructure effected by element diffusion. Design/methodology/approach Al/Cu bimetallic structure is initially manufactured through laser powder bed fusion process. To minimize trial and error, finite element modeling is adopted to simulate temperature changes on the Al-based and Cu-based substrate. Findings The results show that forming pure copper on Al-based substrate can guarantee heat accumulation, providing enough energy for subsequent building. The instantaneous laser energy promotes increase of diffusion activation energy, resulting in the formation of transition zone derived from interdiffusion between Al and Cu atoms. The interface with a thickness of about 22 µm dominated by Kirkendall effect moves towards Al-rich side. The interface microstructure is mainly composed of a-Al, a-Cu and CuAl2 phase. Originality/value The bonding mechanism of Al/Cu interface is atom diffusion-induced chemical reaction. The theoretical basis provides guidance for structural design and production application.

scholarly journals Direct observation of crack formation mechanisms with operando Laser Powder Bed Fusion X-ray imaging

2022 ◽  
pp. 102619
Author(s):  
Hossein Ghasemi-Tabasi ◽  
Charlotte de Formanoir ◽  
Steven Van Petegem ◽  
Jamasp Jhabvala ◽  
Samy Hocine ◽  
...  
Keyword(s):  
Direct Observation ◽  
Crack Formation ◽  
Formation Mechanisms ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
X Ray ◽  
X Ray Imaging
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