scholarly journals Effects of Laser Shock Peening on Microstructure and Properties of Ti–6Al–4V Titanium Alloy Fabricated via Selective Laser Melting

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3261
Author(s):  
Liang Lan ◽  
Ruyi Xin ◽  
Xinyuan Jin ◽  
Shuang Gao ◽  
Bo He ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Titanium Alloy ◽  
Grain Refinement ◽  
Selective Laser Melting ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Laser Melting ◽  
Α Phase ◽  
Shock Peening

Laser shock peening (LSP) is an innovative surface treatment process with the potential to change surface microstructure and improve mechanical properties of additively manufactured (AM) parts. In this paper, the influences of LSP on the microstructure and properties of Ti–6Al–4V (Ti64) titanium alloy fabricated via selective laser melting (SLM), as an attractive AM method, were investigated. The microstructural evolution, residual stress distribution and mechanical properties of SLM-built Ti64 samples were characterized before and after LSP. Results show that the SLM sample was composed of single hcp α’ phase, which deviates from equilibrium microstructure at room temperature: α + β phases. The LSP significantly refines the grains of α’ phase and produces compressive residual stress (CRS) of maximum magnitude up to −180 MPa with a depth of 250 μm. Grain refinement of α’ phase is attributed to the complex interaction of dislocations and the intersection of deformation twinning subjected to LSP treatment. The main mechanism of strength and micro-hardness enhancement via LSP is ascribed to the effects of CRS and α’ phase grain refinement.

Effect of Post Laser Shock Peening on Microstructure and Mechanical Properties of Inconel 718 by Selective Laser Melting

2019 ◽  
Author(s):  
Kuldeep Singh Sidhu ◽  
Yachao Wang ◽  
Jing Shi ◽  
Vijay K. Vasudevan ◽  
Seetha Ramaiah Mannava
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Inconel 718 ◽  
Compressive Residual Stress ◽  
High Energy ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Laser Melting ◽  
Heat Treated ◽  
Shock Peening

Abstract This study investigates the effects of laser shock peening (LSP) on residual stress, near surface modification, and hardness of Inconel 718 (IN718) specimens manufactured by selective laser melting (SLM) technique. Optical microscope and electron backscattered diffraction (EBSD) is used to characterize the microstructures of both heat-treated and as-built specimens. A nanoindentation test is performed to determine the properties such as the hardness of as-built and heat-treated specimens. Afterward, the hardness along the distance from the LSP treated surface is also defined. To investigate the effect of LSP energy on the mechanical properties of specimens, two levels of LSP energy, e.g., low energy LSP (6.37 GW/cm2) and high energy LSP (8.60 GW/cm2), are carried out on selected samples. With the increase in laser energy density, it is found that both compressive residual stress and hardness increase after LSP treatment. The as-built specimens after high energy LSP treatment show the compressive residual stress of −875 MPa, and the surface hardness increases from 468 HV to 853 HV.

scholarly journals Corrosion Behavior of NiTi Alloys Fabricate by Selective Laser Melting Subjected to Femtosecond Laser Shock Peening

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1078
Author(s):  
Long Ma ◽  
Wanqing Li ◽  
Yongzhi Yang ◽  
Yuanxue Ma ◽  
Kai Luo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Femtosecond Laser ◽  
Selective Laser Melting ◽  
Niti Alloy ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Laser Melting ◽  
Corrosion Failure ◽  
Niti Alloys ◽  
Shock Peening

NiTi alloys are commonly used in many fields such as aerospace, mechanical engineering due to their excellent mechanical properties and shape memory effect. In recent years, the emergence of selective laser melting (SLM) technology provides a new method for the preparation of NiTi parts. But the surface corrosion failure of SLM-NiTi is the most common problem. This paper mainly focuses on the research of femtosecond laser shock peening of the surface of SLM-NiTi alloy to improve the corrosion resistance. Selecting different scanning space (1 μm, 3 μm, 5 μm, 10 μm), and analyze the surface morphology of the material through the OM, SEM, EDS and white light interferometer, and investigate the surface nanohardness and corrosion resistance through nanoindentation and electrochemical testing. The research results show that part of the TiO2 is formed under different scanning spaces, and part of NiO is formed when the scanning space is 1μm. At the same time, it is found that the sample under the condition of 10 μm has the most excellent corrosion resistance and nanohardness. The nanohardness reaches 1303 ± 40 HV and the corrosion current density reaches 1.45 ± 0.1 × 10−9 A·cm−2. Proper femtosecond laser treatment can effectively improve the surface strength and corrosion resistance of the NiTi alloys.

Microstructure evolution and mechanical properties of a lamellar near-α titanium alloy treated by laser shock peening

Vacuum ◽  
2021 ◽  
Vol 184 ◽  
pp. 109906
Author(s):  
Weiju Jia ◽  
Yaoxu Zan ◽  
Chengliang Mao ◽  
Silan Li ◽  
Wei Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Microstructure Evolution ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Shock Peening

Laser shock peening: A promising tool for tailoring metallic microstructures in selective laser melting

2019 ◽  
Vol 266 ◽  
pp. 612-618 ◽  
Author(s):  
N. Kalentics ◽  
K. Huang ◽  
M. Ortega Varela de Seijas ◽  
A. Burn ◽  
V. Romano ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Laser Melting ◽  
Promising Tool ◽  
Shock Peening ◽  
Metallic Microstructures
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