Influence of Scanning Speed on Microstructure and Hardness during Laser Cladding High-Cr Cast Iron

2013 ◽  
Vol 395-396 ◽  
pp. 1127-1131 ◽  
Author(s):  
Wei Zhang
Keyword(s):  
Cast Iron ◽  
Laser Cladding ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Fish Bone ◽  
Cladding Layer ◽  
Metallurgical Bonding ◽  
Laser Scanning Speed ◽  
Gas Cavity ◽  
Cladding Layers

The experiments of laser cladding on the surface of 20 steel were made. High-chromium (Cr) cast iron powder was used as cladding material. The microstructure and hardness of laser cladding layers under different scanning speed were studied. The experiments showed that high-Cr cast iron cladding layer had better properties such as minute crystals, high density, no crack, no gas cavity and good metallurgical bonding with base metal. When the scanning speed was low, such as 10mm/min, the microstructure of cladding layer was cellular dendrite. There were much carbide with the shape of fish-bone distributing among cellular grains. Under higher scanning speed (from 100mm/min to 300mm/min), needle-shaped primary cementite would come into being. When laser scanning speed was 500mm/min, the carbide of cladding zone was very thin. With the increasing of laser scanning speed, the average hardness of cladding zone increased from 388HV0.2 to 580 HV0.2.

Research of Composite Coating Composed of Mo Wire and High-Cr Cast Iron Made by Laser Cladding Technology

2013 ◽  
Vol 395-396 ◽  
pp. 1073-1076
Author(s):  
Wei Zhang
Keyword(s):  
Cast Iron ◽  
Laser Cladding ◽  
H13 Steel ◽  
Cladding Layer ◽  
Binding Force ◽  
Average Hardness ◽  
Metallurgical Bonding ◽  
Gas Cavity ◽  
Cast Iron Powder ◽  
Cladding Material

The experiments of laser cladding on the surface of H13 steel were made. Molybdenum (Mo) wire and high-chromium (Cr) cast iron powder were used as cladding material. The microstructure and hardness of laser cladding layer were studied. The experiments showed that Mo wire and high-Cr cast iron cladding layer had better properties such as minute crystals, high density, no crack, no gas cavity and good metallurgical bonding with base metal. There was a slight melting on the surface of Mo wire which would greatly increase the binding force between Mo wire and high-Cr cast iron. Mo wire could make grain refine and limit the growing of carbide. The average hardness of junction zone of Mo wire and high-Cr cast iron was 750HV0.2 which was higher than that of cladding zone composed of high-Cr cast iron (650HV0.2).

A STUDY ON SCAN SPEED RELATIONSHIP WITH MICROSTRUCTURAL EVOLUTION, PHASE COMPOSITION AND MICROHARDNESS OF Ni-CONTAINING INTERMETALLIC COATINGS ON Ti–6Al–4V USING LASER CLADDING TECHNIQUE

2018 ◽  
Vol 25 (08) ◽  
pp. 1950035 ◽  
Author(s):  
O. S. ADESINA ◽  
A. P. I. POPOOLA ◽  
S. L. PITYANA ◽  
D. T. OLORUNTOBA
Keyword(s):  
Laser Cladding ◽  
Laser Scanning ◽  
Gas Flow ◽  
Microstructural Analysis ◽  
Scanning Speed ◽  
Metallurgical Bonding ◽  
Clad Layer ◽  
Fine Microstructure ◽  
Scan Speed ◽  
Laser Scanning Speed

Titanium alloys have been used for variety of engineering applications but their relatively low hardness and low thermal conductivity are shortcomings that have reduced their potential use. In this work, attempts have been made to study the effects of laser scanning speed and admixed fraction of reinforced Ni–Co powders on clad layer formation and its corresponding properties on Ti–6Al–4V. Laser power of 750[Formula: see text]W, beam size of 3[Formula: see text]mm with argon shield gas flow rate of 1.2[Formula: see text]L/min was made constant, while the powders were premixed and deposited on Ti–6Al–4V with varying compositions at different scanning speeds of 0.6 and 1.2[Formula: see text]m/min. The microstructural analysis, phase constituents and hardness properties of Ni–Co intermetallics reinforced clads were also examined. The morphology of the resultant coatings was analyzed using X-ray diffractometry (XRD) and scanning electron microscopy (SEM) equipped with energy dispersive spectrometry (EDS). The research results showed that laser cladding coatings displayed enhanced properties such as fine microstructure and good metallurgical bonding with the substrate containing minimal pores with respect to the substrate. Furthermore, the microstructure revealed the formation of various fractions of interdendritic compounds/intermetallics dispersed within the coating matrix which could be responsible for the increased hardness obtained. The average hardness of the coating was about 856[Formula: see text]HV [Formula: see text], which was about 2.5 times that of the substrate.

scholarly journals Effect of Laser Remelting on Cladding Layer of Inconel 718 Superalloy Formed by Laser Metal Deposition

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4927 ◽  
Author(s):  
Bo Xin ◽  
Jiangyu Ren ◽  
Xiaoqi Wang ◽  
Lida Zhu ◽  
Yadong Gong
Keyword(s):  
Inconel 718 ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Laves Phase ◽  
Laser Metal Deposition ◽  
Laser Remelting ◽  
Cladding Layer ◽  
Average Hardness ◽  
Laser Scanning Speed ◽  
Cladding Layers

The brittle phase (Laves) of Inconel 718 parts formed by laser metal deposition (LMD) represents a bottleneck of the engineering applications. In order to investigate effectiveness of laser remelting (LR) technology on suppressing the formation of Laves phase, different laser scanning speeds of the LR process were adopted to build and remelt the single-pass cladding layers. The evolution of phase composition, microstructural morphology, and hardness of the LMD and LMD + LR specimens were analyzed. The experimental results show that different laser scanning speeds can obviously change the microstructural evolutions, Laves phase, and hardness. A low laser scanning speed (360 mm/min) made columnar dendrite uninterruptedly grow from the bottom to the top of the cladding layer. A high laser scanning speed (1320 mm/min) has a significant effect on refining Laves phase and reducing Nb segregation. When the laser scanning speed of LR process is equal to that of LMD, the cladding layers can be completely remelted and the content of Laves phase of the LMD + LR layer is 22.4% lower than that of the LMD layer. As the laser scanning speed increases from 360 to 1320 mm/min, the mean primary dendrite arm spacing (PDAS) values of the remelting area decrease from 6.35 to 3.28 μm gradually. In addition, the low content of Laves phase and porosity contribute to the growth of average hardness. However, the laser scanning speed has a little effect on the average hardness and the maximum average hardness difference of the LMD and LMD + LR layers is only 12.4 HV.

Microstructure and Hardness of the ZrO2/Ni60A Composite Coating Formed by Feeding Powder Laser-Clad on Circular Surface

2011 ◽  
Vol 138-139 ◽  
pp. 732-736
Author(s):  
Ba Sheng Ouyang ◽  
Run Juan You
Keyword(s):  
Laser Cladding ◽  
Ceramic Powder ◽  
Scanning Speed ◽  
Micro Hardness ◽  
Processing Property ◽  
Laser Process ◽  
Cladding Layer ◽  
Parameter Variations ◽  
Circular Surface ◽  
Cladding Layers

Cladding experiment with parameter variations was presented to manufacture the better processing property coating by laser cladding self-fused Ni-based ceramic powder of ZrO2 composite on the excircle surface of 304 SUS. The influence of the laser process parameters on macroscopic view, microstructure and micro-hardness of the laser cladding layers were investigated. The results show that we can get better coating when laser power is 1.5KW, and that the cladding layer microstructure has the trend of refined framework with the growing of scanning speed; micro-hardness will be higher and distribution from substratum to surface with little fluctuate by optimizing scanning speed.

Effect of laser scanning speed on microstructure and wear properties of T15M cladding coating fabricated by laser cladding technology

2018 ◽  
Vol 110 ◽  
pp. 163-171 ◽  
Author(s):  
Xiangyi Jiao ◽  
Jun Wang ◽  
Canming Wang ◽  
Zhengqi Gong ◽  
Xinxing Pang ◽  
...  
Keyword(s):  
Laser Cladding ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Wear Properties ◽  
Laser Scanning Speed

scholarly journals The Effect of Laser Scanning Speed on Microstructure and Performance of Cr3C2-NiCr Cermet Fabricated by in-situ Laser Cladding

2021 ◽  
pp. X
Author(s):  
Deyuan LOU ◽  
Shaokun YANG ◽  
Sheng MEI ◽  
Qing LIU ◽  
Jian CHENG ◽  
...  
Keyword(s):  
Laser Cladding ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Powder Mixtures ◽  
Laser Scanning Speed ◽  
Nickel Based Alloy ◽  
And Performance ◽  
Microstructure And Performance ◽  
Carbide Content

To explore the effect of laser scanning speed on the microstructure and performance of Cr3C2-NiCr cermet layers fabricated by in-situ laser cladding, Cr3C2-NiCr cermet layers were laser cladded from Ni/Cr/Graphite (25:65:10 wt.%) elemental powder mixtures. The microstructures of the laser cladded cermet layers and the formation mechanism were investigated. In addition, the effect of laser scanning speed on the microstructure, friction and corrosion performance of the Cr3C2-NiCr cermet layers was studied. The results indicated that the in-situ laser cladded Cr3C2-NiCr cermet layers were composed of NiCr binder and Cr3C2. The laser scanning speed had a significant influence on the carbide content, composition and size. Furthermore, it affected the in-situ laser cladded cermet layer’s hardness and wear resistance. The corrosion resistance of the in-situ laser cladded cermet layer was superior to that of laser cladded nickel-based alloy and was improved with decreasing laser scanning speed.

Dissolution Behavior of WC Reinforced Particles on Carbon Steel Surface during Laser Cladding Process

2012 ◽  
Vol 430-432 ◽  
pp. 137-141 ◽  
Author(s):  
Zhong Zhang ◽  
Hong Xi Liu ◽  
Xiao Wei Zhang ◽  
Sheng Wei Ji ◽  
Ye Hua Jiang
Keyword(s):  
Carbon Steel ◽  
Composite Coating ◽  
Laser Cladding ◽  
Laser Scanning ◽  
Energy Dispersive Spectrometer ◽  
Scanning Speed ◽  
Decomposition Reaction ◽  
Medium Carbon Steel ◽  
Dissolution Behavior ◽  
Laser Scanning Speed

Ni60WC35 self-fluxing composite coating was fabricated by transverse-flow CO2 laser apparatus on 45 medium-carbon steel surfaces. The microstructure and phase transform behavior of WC reinforced particles under the laser cladding conditions was investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy-dispersive spectrometer (EDS). The results show that laser scanning speed has a great important influence on the microstructure of Ni-based WC composite coating, WC particles has a transition to the Ni-based coating. The main feature of WC particle is its edge hard phase has transformed into needle phase, and the needle phase areas increase with the decrease of the laser scanning speed. Some WC particles turn into needle clusters structure, and then white block phase. In addition, WC particle has some microscopic defects, and the surface priority defect can be dissolved. When the pool temperature rises to 1250°C, WC decomposition reaction become W2C and C. The elements diffusion can promote the dissolution of WC particles when the pool temperature rises continuously.

The Effect of Scanning Power on AISI 434L Stainless Steel-Based Composite Laser Cladding Coatings

2015 ◽  
Vol 1095 ◽  
pp. 636-640
Author(s):  
Si Yu Wang ◽  
You Zheng Sun ◽  
Jin Bao Li ◽  
Kuai Kuai Guo ◽  
Ben Rong Hai ◽  
...  
Keyword(s):  
Solid Solution ◽  
Stainless Steel ◽  
Laser Cladding ◽  
Laser Scanning ◽  
Raw Material ◽  
Cladding Layer ◽  
Two Phases ◽  
Cladding Layers ◽  
Composite Laser

In this experiment, several coatings, which were used 434L ferrite stainless steel powders and B4C powders as raw material, were prepared under different laser scanning power. The samples of the coatings were detected by XRD and EDS, and observed by OM and SEM. The results are shown as follow: when laser scanning power is 1800W, the cladding layer contains FeB and CrB6, as scanning power increasing, these two phases disappear in cladding layer, and Fe2B and CrB are detected in the layer. Fe2B, CrFeB, (Cr Fe)7C3, Fe-Cr solid solution are found in all samples no matter which laser scanning power are changed to prepare cladding layers The morphology of phases rich boron and carbon transform from an irregular layer-like shape to a cycle-like or a bar-like one with the scanning power increasing.

scholarly journals Investigation on Microstructure, Hardness, and Corrosion Resistance of Mo–Ni–B Coatings Prepared by Laser Cladding Technique

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 856 ◽  
Author(s):  
Xiaojie Ni ◽  
Shengze Wang ◽  
Yuantao Zhao ◽  
Wenge Li ◽  
Xiong Jiao
Keyword(s):  
Corrosion Resistance ◽  
Laser Cladding ◽  
Laser Scanning ◽  
Bottom Layer ◽  
Scanning Speed ◽  
Corrosion Current ◽  
Corrosion Resistant ◽  
Cermet Coatings ◽  
Laser Scanning Speed ◽  
Corrosion Resistant Coatings

The hard and corrosion resistant coatings of Mo2NiB2 cermet were prepared by the laser cladding technique. The influences of the Mo:B ratio and the laser scanning speed on the microstructure and property of the Mo2NiB2 cermet coatings were investigated. The results showed that the laser scanning speed of 1.5 mm/s and the Mo:B ratio of 1 were more beneficial to the formation of Mo2NiB2 cermet than 2.0 mm/s and 0.8, 1.2, respectively. The amount of the Mo2NiB2 ceramic phases were decreased from the top layer to the bottom layer of the coating. The changes of microstructure and composition led to the changes of hardness and corrosion resistance of the Mo2NiB2 cermet coatings. The coating prepared at the Mo:B ratio of 1 and the scanning speed of 1.5 mm/s possessed the highest hardness, and the hardness gradually decreased from the top layer to the bottom layer of the coating. The formation of Mo2NiB2 and {FeM} phases led to the enhanced corrosion resistance of the Mo2NiB2 cermet coatings, and the coating prepared at the Mo:B ratio of 0.8 possessed the best corrosion resistance and the minimum corrosion current.

Microstructure and Wear-Resistance Property of Laser Cladding Layer on GH710

2012 ◽  
Vol 479-481 ◽  
pp. 88-92
Author(s):  
Bin Hu ◽  
Fang You Hu ◽  
Xu Ren Huang ◽  
De Xian Yi ◽  
Pei Zhong Zhao ◽  
...  
Keyword(s):  
Laser Cladding ◽  
Friction And Wear ◽  
Sliding Friction ◽  
Melting Line ◽  
Cladding Layer ◽  
Metallurgical Bonding ◽  
Columnar Grains ◽  
Bonding Zone ◽  
Bottom To Top ◽  
Cladding Layers

To repair the damages of aero blades, laser cladding on GH710 substrate using NiCrMoNb powder by CO2 laser was carried out. The microstructure and microhardness of cladding layers were investigated. The property of dry sliding friction and wear in the air was tested. It was found that the cladding layer was well combined with the substrate. The white narrow metallurgical bonding zone was about 15~20μm. The microstructure transformed from coarse columnar grains to fine dendritic grains from bottom to top and the net-like grains were fabricated on the surface. The axis of columnar grains was perpendicular to the direction of the melting line. Columnar grains had the scale of 10~15μm on the width and 50~60μm in the axis direction. The area of the crystal lattice varied from 2μm×4μm to 5μm×9μm. The microhardness of cladding layer, metallurgical bonding zone and the substrate changed gradually. The microhardness was 450HV, 40%~50% higher than that of the substrate. The wearing capacity was 50%~55% of that of the substrate. The main form of abrasion was grain-abrasion and adhesion-abrasion.

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