Liquation and Crystallization Cracks in Aluminum Alloy AA2024 during Selective Laser Melting

2021 ◽  
Vol 410 ◽  
pp. 203-208
Author(s):  
I.S. Loginova ◽  
N.A. Popov ◽  
A.N. Solonin
Keyword(s):  
Aluminum Alloy ◽  
Selective Laser Melting ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Melting Zone ◽  
Alloying Elements ◽  
Laser Melting ◽  
Laser Scanning Speed ◽  
Positive Effect

In this work we studied the microstructure and microhardness of standard AA2024 alloy and AA2024 alloy with the addition of 1.5% Y after pulsed laser melting (PLM) and selective laser melting (SLM). The SLM process was carried out with a 300 W power and 0.1 m/s laser scanning speed. A dispersed microstructure without the formation of crystallization cracks and low liquation of alloying elements was obtained in Y-modified AA2024 aluminum alloy. Eutectic Al3Y and Al8Cu4Y phases were detected in Y-modified AA2024 aluminum alloy. It is led to a decrease in the formation of crystallization cracks The uniform distribution of alloying elements in the yttrium-modified alloy had a positive effect on the quality of the laser melting zone (LMZ) and microhardness.

scholarly journals In Situ Mo(Si,Al)2-Based Composite through Selective Laser Melting of a MoSi2-30 wt.% AlSi10Mg Mixture

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3720 ◽  
Author(s):  
Tatevik Minasyan ◽  
Sofiya Aydinyan ◽  
Ehsan Toyserkani ◽  
Irina Hussainova
Keyword(s):  
High Temperature ◽  
Selective Laser Melting ◽  
Laser Power ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Laser Melting ◽  
Structural Applications ◽  
Laser Scanning Speed ◽  
Fusion Approach

The laser power bed fusion approach has been successfully employed to manufacture Mo(Si,Al)2-based composites through the selective laser melting of a MoSi2-30 wt.% AlSi10Mg mixture for high-temperature structural applications. Composites were manufactured by leveraging the in situ reaction of the components during printing at 150–300 W laser power, 500–1000 mm·s−1 laser scanning speed, and 100–134 J·mm−3 volumetric energy density. Microcomputed tomography scans indicated a negligible induced porosity throughout the specimens. The fully dense Mo(Si1-x,Alx)2-based composites, with hardness exceeding 545 HV1 and low roughness for both the top (horizontal) and side (vertical) surfaces, demonstrated that laser-based additive manufacturing can be exploited to create unique structures containing hexagonal Mo(Si0.67Al0.33)2.

scholarly journals Modeling of Residual Stress Distribution for Components Manufactured by Selective Laser Melting

2019 ◽  
Vol 224 ◽  
pp. 05006
Author(s):  
Tong Ye ◽  
Xiaohui Jiang ◽  
Miaoxian Guo ◽  
Vladimir Kuptsov ◽  
Sergey Fedorov
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Selective Laser Melting ◽  
Laser Power ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Residual Stress Distribution ◽  
Laser Melting ◽  
Laser Scanning Speed ◽  
Formed Part

In this paper, the selective laser melting (SLM) simulation analysis of components is carried out. The residual stress distribution of the formed part was predicted, and the influence of process parameters such as exposure time, laser power and laser scanning speed on the residual stress of the SLM formed part was analyzed. It was found that the residual stress concentration of the formed part was in the middle of the upper surface or the bottom surface. In addition, the laser power and the laser scanning speed have a great influence on the residual stress of the formed part. The results of this study lay a theoretical and experimental basis for the optimization of residual stress and quality control of SLM components.

scholarly journals Development of new approaches to the study of pitting corrosion resistance of stainless steels obtained by selective laser melting

2019 ◽  
Vol 121 ◽  
pp. 01011
Author(s):  
Olga Parmenova ◽  
Svetlana Mushnikova ◽  
Vitaliy Bobyr ◽  
Evgeniy Samodelkin
Keyword(s):  
Corrosion Resistance ◽  
Selective Laser Melting ◽  
Pitting Corrosion ◽  
Stainless Steels ◽  
Laser Scanning ◽  
Corrosion Behaviour ◽  
Steel Corrosion ◽  
Scanning Speed ◽  
Laser Melting ◽  
Initial State

This paper presents the results of comparative corrosion resistance studies of stainless steels manufactured by selective laser melting (SLM) in the initial state with subsequent heat treatment and machining. Pitting corrosion tests are carried out, according to ASTM G48 method A in 10% FeCl3·6H2O solution at elevated temperature and exposure time for 5h. The studies were performed on the AISI 321 and AISI 316L stainless steels manufactured by SLM. It was obtained that laser scanning speed decrease led to density rise by other SLM parameters being equal. Porosity affected to the stainless steel corrosion behaviour significant. Metal density decrease resulted to corrosion rate rise. Microstructure examination showed that pitting corrosion development depended on surface steel condition.

Numerical Study of Porosity Formation With Implementation of Laser Multiple Reflection in Selective Laser Melting

2019 ◽  
Author(s):  
Bo Cheng ◽  
Charles Tuffile
Keyword(s):  
Selective Laser Melting ◽  
Laser Scanning ◽  
Numerical Study ◽  
Fluid Model ◽  
Melting Process ◽  
Scanning Speed ◽  
Powder Layer ◽  
Cfd Model ◽  
Laser Melting ◽  
Porosity Formation

Abstract In selective laser melting (SLM) process, the build part quality is determined by process parameters such as laser scanning speed and power. The presence of porosity, a major printing defect that significantly affects part performance, may arise in laser melting process due to insufficient or excess energy input. The improvement of build quality heavily depends on fundamental understanding of porosity formation in the SLM process. In this study, the discrete element method (DEM) has been utilized to simulate the creation of a newly deposited powder layer. A computational fluid dynamics (CFD) model was developed to simulate the melting and solidification process of Ti-6Al-4V powders in the SLM process. The thermo-fluid model includes effect of surface tension and recoil pressure as well as laser ray multi-reflection in keyhole. The predictability of the developed CFD model has been validated against literature experimental data. It is found that the collapse of an unstable deep keyhole was responsible for the formation of pores. In addition, higher laser scanning speeds tend to form unstable melt pools, e.g., melt pool break-up.

Effects of the Processing Parameters on the Forming Quality of Stainless Steel Parts by Selective Laser Melting

2011 ◽  
Vol 189-193 ◽  
pp. 3668-3671 ◽  
Author(s):  
Qing Song Wei ◽  
Xiao Zhao ◽  
Li Wang ◽  
Rui Di Li ◽  
Jie Liu ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Selective Laser Melting ◽  
Molten Pool ◽  
Laser Power ◽  
Single Layer ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Powder Layer ◽  
Laser Melting

Selective Laser Melting (SLM) can produce high-performance metal parts with complex structures. However, it’s difficult to control the processing parameters, because many factors involves. From the perspective of the molten pool, the study focuses on the effects of processing parameters, including scanning speed, laser power, scanning space, layer thickness, and scanning strategies, on the surface quality, the balling effect, the density of SLM parts, by conducting experiments of single track, single layer and block forming. The results show that the quality of the molten pool is affected by laser power and scanning speed. Scanning drove in the strategy of “jumping and turning”，a smooth surface and a less balling effect will be obtained. The thicker the powder layer is, the lower density will be obtained. The optimal parameters from series of experiments are: laser power of 98W; scanning speed of 90mm/s; scanning space of 0.07mm; layer thickness of 0.1mm; and scanning strategy of “jumping and turning”.

Sign in / Sign up

Export Citation Format

Share Document