Microstructure and Grain Abrasion Properties of Cr3C2-NiCr Coating Prepared by Laser Cladding Method

2012 ◽  
Vol 271-272 ◽  
pp. 3-7
Author(s):  
Long Wei ◽  
Zong De Liu ◽  
Xin Zhi Li ◽  
Ming Ming Yuan ◽  
Cheng Yuan Zhong

Cr3C2-NiCr has high quality of wear resistant properties and is widely used in abrasive environment. In this paper, Cr3C2-NiCr coating was prepared on 45 steel by laser cladding technology. Analysis and research of the coatings were achieved by SEM and XRD to determine the main component and the different region on coatings. The hardness and the element component were investigated by micro-hardness tester and EDS. Abrasion tests were performed to contrast the wear resistance of two materials. The results indicate that the hardness of the coatings is nearly 3 times as the substrate. The coatings are well combined with the substrate and the phase of Cr3C2 has a large proportion in the coatings. Abrasion tests show that the average of wear rate on substrate is 5.2 times as the coatings.

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2541 ◽  
Author(s):  
Qiu-Lian Dai ◽  
Can-bin Luo ◽  
Fang-yi You

Laser cladded WC/Fe coatings have the advantages of low cost and high abrasion wear resistance. However, cracks always appear in WC/Fe coatings, which limits their industrial application. In this paper, the co-effects of the re-melting process, heat treatments, and amount of Co element on the cracking susceptibility, microstructures, and mechanical properties of WC/Fe laser cladding coatings were studied. Experimental results show that re-melting process is helpful to improve the surface quality of the coating and to reduce the cracking susceptibility. The hardness of the coating decreases slightly but distributes more uniformly. Cracks in the coating can be inhibited effectively by preheating the substrate to 250 °C and maintaining the temperature during the laser cladding process, as well as applying an annealing treatment at 300 °C for 1 h. Heat treatment also results in a slight decrease in the hardness. Crack initiation cannot be restrained completely by applying the above two methods when laser cladding a big area of coating. On the basis of the above two methods, addition of Co element to the coating can further improve its toughness and decrease the crack susceptibility. Crack-free WC/Fe coating can be manufactured when 8% Co is added, and its wear resistance is much better than that of the hardened medium steel, especially when the wear time is long.


2008 ◽  
Vol 375-376 ◽  
pp. 338-342 ◽  
Author(s):  
Xia Ji ◽  
Jian Zhong Zhou ◽  
Hua Feng Guo ◽  
Da Peng Xu

This paper presents an experimental investigation on the metal components fabricated by laser cladding. In the present study, two process of laser cladding were conducted, that is pre-placed powder cladding and coaxial powder-feed cladding. The effect of processing parameters was studied and optimum set of parameters for the superior surface quality was established by employing the orthogonal design. The fabricated components were subjected to metallographic examinations and micro-hardness measurement. Results indicated that the microstructure of coaxial cladding components was finer than pre-placed powder cladding components. The micro-hardness of the fabricated specimen along and vertical the scanning direction were measured using a HVS-1000 micro-hardness tester with a 200 g applied load. Analysis of the physical properties provided further evidence of differences in micro-hardness produced by different process conditions, and the average micro-hardness value of pre-placed power cladding layer was lower than the coaxial powder-feed cladding layer.


2013 ◽  
Vol 631-632 ◽  
pp. 167-171
Author(s):  
Wei Xiang Zhang ◽  
Shuang Min Du

For effective bonding of Magnesium alloy, Cu foil was used as the interlayer to conduct the diffusion bonding experiment of AZ31B alloy. The microstructure and properties of the diffusion bonding joint was analyzed by means of SEM, EDS and micro-hardness tester. Experiment results show that compact bonding joint was obtained at the temperature of 480°C, holding time of 30 minutes, pressure of 10 MPa and the vacuum degree of 1.0×10-2Pa. The bonding joint consists of a interfacial diffusion region which is a mixture of Mg2Cu, MgCu2, and Mg(Cu) solid solution, and the transitional zone which is composed of Mg(Cu,Al) solid solution base and Mg17(Al, Cu)12 phase. Within the bonding joint,the micro-hardness shows a step pattern of increasing, which is well accord with the the microstructural feature of the joint.This trial has prove that using Cu as the interlayer is effective to improve the quality of the AZ31B bonding joint.


2017 ◽  
Vol 24 (Supp01) ◽  
pp. 1850009 ◽  
Author(s):  
H. X. ZHANG ◽  
H. J. YU ◽  
C. Z. CHEN ◽  
J. J. DAI

In order to improve the wear resistance of Ti alloys, different mass ratios of Ti-Si-Al powders were designed to fabricate hard phases reinforced intermetallic matrix composite coatings on the Ti-6Al-4V substrate by laser cladding. The corresponding coatings were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and high resolution transmission microscopy (HRTEM). The HV-1000 hardness tester and MM200 wear test machine were employed to test the hardness and the wear resistance of the composite coatings, respectively. The composite coatings mainly consisted of the reinforcements of Ti5Si3, Ti3AlC2 and Ti7Al5Si[Formula: see text] and the matrix of Ti3Al, TiAl, TiAl3 and [Formula: see text]-Ti. The micro-hardness of the Ti-35Al-15Si coating was from 956 HV[Formula: see text] to 1130 HV[Formula: see text], which was approximately 3–4 times of the substrate and the highest in the three samples. The wear rate of the Ti-35Al-15Si coating was 0.023[Formula: see text]cm3[Formula: see text][Formula: see text][Formula: see text]min[Formula: see text], which was about 1/4 of the Ti-6Al-4V substrate. It was the lowest in the three samples.


2007 ◽  
Vol 539-543 ◽  
pp. 1159-1164
Author(s):  
Mirko Sokovic ◽  
Leszek Adam Dobrzański ◽  
Janez Kopač ◽  
Ladislav Kosec

The paper presents investigation results of tribological and cutting properties of the coatings deposited with the PVD and CVD techniques on cutting inserts made from the Al2O3 + TiC tool ceramics. Tests were carried out on the inserts made from ceramics, uncoated and PVD or CVD-coated with gradient, mono-, multilayer and multicomponent hard wear resistant coatings composed of TiN, TiCN, TiAlN, TiAlSiN and Al2O3 layers. Substrate hardness tests and micro hardness tests of the deposited coatings were made on the ultra-micro-hardness tester. It was demonstrated, basing on the technological cutting tests of grey cast iron (260 HB), that putting down onto the tool ceramics the thin anti-wear PVD and CVD coatings increases their abrasion wear resistance, which has a direct effect on extending tool life of the cutting edge.


2006 ◽  
Vol 13 (05) ◽  
pp. 645-654 ◽  
Author(s):  
RUILIANG BAO ◽  
HUIJUN YU ◽  
CHUANZHONG CHEN ◽  
BIAO QI ◽  
LIJIAN ZHANG

Laser cladding is an advanced surface modification technology with broad prospect in making wear-resistant coating on titanium alloys. In this paper, the influences of laser cladding processing parameters on the quality of coating are generalized as well as the selection of cladding materials on titanium alloys. The microstructure characteristics and strengthening mechanism of coating are also analyzed. In addition, the problems and precaution measures in the laser cladding are pointed out.


2012 ◽  
Vol 19 (02) ◽  
pp. 1250009 ◽  
Author(s):  
PENG LIU ◽  
WEI GUO ◽  
DAKUI HU ◽  
HUI LUO ◽  
YUANBIN ZHANG

The synthesis of hard composite coating on titanium alloy by laser cladding of Al/Fe/Ni+C/Si3N4 pre-placed powders has been investigated in detail. SEM result indicated that a composite coating with metallurgical joint to the substrate was formed. XRD result indicated that the composite coating mainly consisted of γ- (Fe, Ni) , FeAl , Ti3Al , TiC , TiNi , TiC0.3N0.7 , Ti2N , SiC , Ti5Si3 and TiNi . Compared with Ti-3Al-2V substrate, an improvement of the micro-hardness and the wear resistance was observed for this composite coating.


2014 ◽  
Vol 556-562 ◽  
pp. 189-192 ◽  
Author(s):  
Shun Min Zhu ◽  
Ya Dong Zhang

With the laser cladding technology, 70%Ni60A+30%WC cladding layer was cladded on the surface of Q345 steel. And the phase, microstructure and wear resistance of cladding layer were analyzed. Experiments show that the Ni-based WC alloy laser cladding treatment on Q345 steel surface have a great upgrade on grain refinement, surface hardness and wear-resistance of Q345 steel surface.


2011 ◽  
Vol 189-193 ◽  
pp. 830-833
Author(s):  
Yong Tao Zhao ◽  
Wen Xue Li ◽  
Jun Wei Zhou

The laser cladding of Fe power technology was used to repair worn plunger piston surface. The microstructure of cladding layer, binder course and the matrix were observed by OM and SEM. Besides, the micro-hardness of different zones was measured through micro-hardness testing. The results show that the matrix metal microstructure of plunger piston is made of ferrite and austenite. By laser cladding Fe-based power on base metal, the cladding layer grain is fine and uniform, grain growth has obvious direction and finally become dendrites oriented, the microstructure of cladding layer is both second-phase hard particles and Fe-based solutes. The combination between matrix and cladding layer is smooth, belong to metallurgy bonding. The hardness of cladding layer is higher than that of other parts in three parts, the max value of micro-hardness is about 1250HV, it can agree with wear resistance need of plunge piston surface.


2010 ◽  
Vol 154-155 ◽  
pp. 959-963
Author(s):  
Zhao Mei Xu ◽  
Zong Hai Hong

This paper presents an experimental research on the metal parts manufactured by laser cladding. The present studies showed two processes were conducted ,including coaxial powder-feed cladding and pre-placed powder cladding. The effect of processing parameters were studied and optimum set of parameters for the superior surface quality was established by employing the orthog -onal design. The manufactured parts were subjected to metallographic examination and micro -hardness measurement. Results showed that the microstructure of coaxial cladding parts was better than that of pre-placed powder cladding parts. The micro-hardness of the manufactured specimen along and vertical the scanning direction were measured using a HVS-1000 micro-hardness tester with a 200g applied load. Analysis of the physical properties provided further evidence of differences in micro-hardness produced by different process conditions, and the average micro -hardness value of pre-placed power cladding layer was lower than that of the coaxial powder-feed cladding layer.


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