scholarly journals Effect of Laser Metal Deposition Parameters on the Characteristics of Stellite 6 Deposited Layers on Precipitation-Hardened Stainless Steel

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5662
Author(s):  
Ali Ebrahimzadeh Pilehrood ◽  
Amirhossein Mashhuriazar ◽  
Amir Hossein Baghdadi ◽  
Zainuddin Sajuri ◽  
Hamid Omidvar
Keyword(s):  
Stainless Steel ◽  
Laser Energy ◽  
Focal Length ◽  
Low Frequency ◽  
Scanning Speed ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Stellite 6 ◽  
Long Run ◽  
High Scanning Speed

Laser metal deposition (LMD) is one of the manufacturing processes in the industries, which is used to enhance the properties of components besides producing and repairing important engineering components. In this study, Stellite 6 was deposited on precipitation-hardened martensitic stainless steel (17-4 PH) by using the LMD process, which employed a pulsed Nd:YAG laser. To realize a favor deposited sample, the effects of three LMD parameters (focal length, scanning speed, and frequency) were investigated, as well as microstructure studies and the results of a microhardness test. Some cracks were observed in the deposited layers with a low scanning speed, which were eliminated by an augment of the scanning speed. Furthermore, some defects were found in the deposited layers with a high scanning speed and a low frequency, which can be related to the insufficient laser energy density and a low overlapping factor. Moreover, various morphologies were observed within the microstructure of the samples, which can be attributed to the differences in the stability criterion and cooling rate across the layer. In the long run, a defect-free sample (S-120-5.5-25) possessing suitable geometrical attributes (wetting angle of 57° and dilution of 25.1%) and a better microhardness property at the surface (≈335 Hv) has been introduced as a desirable LMDed sample.

Influence of laser absorption by water- and gas-atomised powder feedstock on Laser Metal Deposition of AISI 431 stainless steel

2021 ◽  
pp. 102242
Author(s):  
Andre Hatem ◽  
Christiane Schulz ◽  
Thomas Schlaefer ◽  
Jeff T. Boobhun ◽  
Nikki Stanford ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Laser Absorption ◽  
Powder Feedstock

Cladding of Stellite-6/WC Composites Coatings by Laser Metal Deposition

2018 ◽  
Vol 941 ◽  
pp. 1645-1650 ◽  
Author(s):  
Takahiro Kunimine ◽  
Ryusei Miyazaki ◽  
Yorihiro Yamashita ◽  
Yoshinori Funada ◽  
Yuji Sato ◽  
...  
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Metal Deposition ◽  
Matrix Composites ◽  
Laser Metal Deposition ◽  
Feeding Rates ◽  
Coating Materials ◽  
Cross Sectional ◽  
Stellite 6 ◽  
Powder Feeding

This study aims to investigate the microstructure and hardness of multi-layered Stellite-6/WC metal-matrix composites coatings on metallic substrates cladded by laser metal deposition (LMD) for improvement of wear and corrosion resistances. As coating materials, Stellite-6 and WC-12wt.%Co powders were selected. Powder mixtures having various mixing-ratios of Stellite-6 and WC-12wt.%Co were provided vertically on S45C substrates by controlling powder feeding rates of the two powder feeders, individually. Stellite-6/WC composites which consist of three layers with different compositions were cladded on the S45C substrates by laser melting. Cross-sectional microstructure observation was carried out by using an optical microscope (OM). Vickers microhardness tests were conducted to evaluate hardness of the cladding layers and substrates. The experimental results demonstrate that hard multi-layered Stellite-6/WC metal-matrix composites coatings were successfully cladded on the S45C substrates. Property gradients in the Stellite-6/WC composites could be made due to the position-dependent chemical composition and microstructure made by controlling powder feeding rates of an LMD system.

scholarly journals Evaluation of the quality of layers applied by LDT laser metal deposition

2018 ◽  
Vol 19 (6) ◽  
pp. 591-596
Author(s):  
Andrzej Mazurkiewicz ◽  
Andrzej Poprzeczka
Keyword(s):  
Heat Affected Zone ◽  
Heat Dissipation ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Cross Sectional ◽  
Weld Overlay ◽  
The Cross

The article presents the results of a study of C45 carbon steel hardfacing using laser metal deposition with Stellit Co-21 powder. The microstructure of the cross-section of samples prepared with different scanning speed and the amount of used powder at constant laser power was observed. Analyzing the cross-sectional areas of the samples, it was found that, at specific production parameters, cracks occur in weld overlay, which should be associated with the amount of heat supplied and discharged, especially at the unheated basis.This may be confirmed by the presence of deposits of weakly branched dendrites in the microstructure, which should be related to the directional heat dissipation process and rapid directional crystallization. It is possible to regulate these phenomena by selecting appropriate processing parameters. The microstructure analysis of cross-sectional areas of samples after hardfacing using LDT technique indicates good metallurgical quality of the deposit with a small heat affected zone of about 660÷760m. The microhardness measurements on the sample cross-sections indicated a wide micohardness distribution ranging from 510HV1 in the weld overlay, about 410HV1 in the heat affected zone, to 270HV1 in the C45 steel base.

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