scholarly journals Erratum: Elshazli et al. Laser Surface Modification of TC21 (α/β) Titanium Alloy Using a Direct Energy Deposition (DED) Process. Micromachines 2021, 12, 739

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1078
Author(s):  
Ahmed Magdi Elshazli ◽  
Ramadan N. Elshaer ◽  
Abdel Hamid Ahmed Hussein ◽  
Samar Reda Al-Sayed

In the original article [...]

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 739
Author(s):  
Ahmed Magdi Elshazli ◽  
Ramadan N. Elshaer ◽  
Abdel Hamid Ahmed Hussein ◽  
Samar Reda Al-Sayed

The TC21 alloy (Ti-6Al-3Mo-1.9Nb-2.2Sn-2.2Zr-1.5Cr) is considered a new titanium alloy that replaced the commercial Ti-6Al-4V alloy in aerospace applications due to its higher operating temperatures. Recently, direct energy deposition was usually applied to enhance the hardness, tribological properties, and corrosion resistance for many alloys. Consequently, this study was performed by utilizing direct energy deposition (DED) on TC21 (α/β) titanium alloy to improve their mechanical properties by depositing a mixture powder of stellite-6 (Co-based alloy) and tungsten carbides particles (WC). Different WC percentages were applied to the surfaces of TC21 using a 4 kW continuous-wave fiber-coupled diode laser at a constant powder feeding rate. This study aimed to obtain a uniform distribution of hard surfaces containing undissolved WC particles that were dispersed in a Co-based alloy matrix to enhance the wear resistance of such alloys. Scanning electron microscopy, energy dispersive X-ray analysis (EDAX), and X-ray diffractometry (XRD) were used to characterize the deposited layers. New constituents and intermetallic compounds were found in the deposited layers. The microhardness was measured for all deposited layers and wear resistance was evaluated at room temperature using a dry sliding ball during a disk abrasion test. The results showed that the microstructure of the deposited layer consisted of a hypereutectic structure and undissolved tungsten carbide dispersed in the matrix of the Co-based alloy that depended on the WC weight fraction. The microhardness values increased with increasing WC weight fraction in the deposited powder by more than threefold as compared with the as-cast samples. A notable enhancement of wear resistance of the deposited layers was thus achieved.


2020 ◽  
Vol 277 ◽  
pp. 116420 ◽  
Author(s):  
Min-seob Kim ◽  
Wook-jin Oh ◽  
Gyeong-yoon Baek ◽  
Yeong-kwan Jo ◽  
Ki-yong Lee ◽  
...  

2021 ◽  
Vol 15 (3) ◽  
pp. 8310-8318
Author(s):  
A. Q. Zaifuddin ◽  
F. Zulhilmi ◽  
M.H. Aiman ◽  
M.M. Quazi ◽  
M. Ishak

Titanium alloys are widely utilized in laser heating applications. However, it has poor optical properties due to low laser energy absorption. Nevertheless, a higher energy absorption can be realized by modifying the surface profile through increasing the surface roughness. In this present work, the laser surface modification (LSM) process was carried out to increase the roughness on surface of Ti6Al4V titanium alloy. Subsequently, the surface characterization and surface roughness were analysed by using the 3D optical microscope. The effect of laser power on the increment of surface roughness was investigated. It was revealed that an increase in laser power during LSM process could increase the surface roughness. The result shows that, the surface roughness of titanium alloy increased 27 times when modified with the highest laser power (27W) compared to the gritted surface. Furthermore, the modified surface by LSM will be heated using laser radiation in order to analyse the effect of surface roughness towards laser heating temperature. Depending on the value of the power during laser heating, the maximum temperature measured could be increased 27% corresponding to a gritted flat reference surface.


2021 ◽  
pp. 109626
Author(s):  
Jiaxuan Chi ◽  
Zhongyi Cai ◽  
Hepeng Zhang ◽  
Hongqiang Zhang ◽  
Wei Guo ◽  
...  

2021 ◽  
Vol 2131 (5) ◽  
pp. 052083
Author(s):  
L V Belyaev ◽  
A V Zhdanov

Abstract The effect of laser modification of the surface on the value of the coefficient of elasticity, hardness, coefficient of friction and the amount of wear of the counter body when testing products made of a deformable titanium alloy was investigated. It was found that the indicators of hardness and wear resistance of a titanium alloy depend on the modes of laser modification. These dependencies are extreme in nature, they have maxima and minima. The quantitative values of hardness and wear resistance indicators for the specified material before and after laser treatment of its surface in various modes are given.


Author(s):  
M. A. Montealegre ◽  
G. Castro ◽  
J. L. Arias ◽  
A. Fernández-Vicente ◽  
J. Vázquez

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