Microstructure and Property of In-Situ TiC Reinforced Co-Based Composite Coatings by Laser Cladding

2019 ◽  
Vol 11 (12) ◽  
pp. 1798-1805 ◽  
Author(s):  
Xiumin Quan ◽  
Lin Ding

In order to improve the wear resistance of Co-based alloy coatings, in-situ TiC reinforced Co-based composite coatings were prepared on 45 steel surface by laser cladding Co-based alloy, Ti and C powders. The effect of (Ti + C) addition on the microstructure and wear resistance of in-situ TiC reinforced Co-based composite coatings was investigated systematically. The results showed that TiC and Co3Ti phases were detected in the in-situ TiC reinforced Co-based composite coatings, besides γ-Co and Cr23C6. The in-situ TiC reinforced Co-based composite coatings was mainly composed of planar crystals in the binding zone, dendrites in the bottom and equiaxed crystals in the upper. With the increase of (Ti + C) addition, the number of short rod-like dendrites and equiaxed crystals was gradually increased, the microstructure was more fine and uniform. The microhardness of the composite coatings was improved gradually, and the maximum improvement in the microhardness was 35.7%, for 30.0 wt.% (Ti + C) addition. The mass loss of the composite coatings was firstly reduced and then increased, the lowest value was 10.5 mg for 20.0 wt.% (Ti + C) addition, which was 59.7% of that of Co-based alloy coatings, and the wear mechanism of the composite coatings after adding (Ti + C) was the abrasive wear. These results indicated that adding (Ti + C) had a significant influence on the properties of the composite coatings, and were consistent with the calculated results of applied multivariate statistical analysis.

2020 ◽  
pp. 2050046
Author(s):  
TIANWEI YANG ◽  
ZHAOHUI WANG ◽  
SHIHAI TAN ◽  
FU GUO

To increase the strength and wear resistance of material surfaces, various combinations of B4C and 80TiFe powder were mixed into a Fe60 self-fluxing alloy powder; the composite coatings reinforced by TiB2–TiC were successfully prepared on Q235 steel surfaces by laser cladding. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) were used to study the microstructure and chemical and phase composition. Microhardness and wear testers were used to investigate the mechanical properties. The results show that the interfaces of composite coatings and substrate materials are excellent for metallurgical bonding. The block-like TiB2 particles and flower-like TiC particles are uniformly distributed in the cladding coating. When the mass fraction of the mixed powder is 30%, the average microhardness of the coating is approximately 1100 HV[Formula: see text], which is 50% higher than that without the mixed powder, and demonstrates the best wear with a performance twice as better as that of the substrate.


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.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Nga Pham Thi-Hong

Laser cladding of Co50 alloy coating and Co50 composite coatings doped with 10, 20, and 30 wt.% TiC particles was performed on the H13 steel surface. The effects of TiC concentration on the phase composition, microstructure, and microhardness of the coatings were studied. The results indicated that, in 10% TiC coating, the “bright band” is a quite flat-growth tissue, while with 20% TiC, the “white bright band” contains a large amount of black TiC particles. The composite coating Co50, 10% TiC, and 20% TiC samples can clearly distinguish the cladding zone, bonding zone, and heat-affected zone, and a good metallurgical bond is formed between the coating and the substrate. The 30% TiC coating and the substrate are not well bonded, which is attributed to the high TiC content in the coating; however, it has the best surface morphology, and there is no porosity on the surface. 10% TiC coatings have poor surface quality, show a spraying material phenomenon on two side edges which is quite serious, and a lot of porosity on the surface of the coating. In addition, 10% TiC coating includes the original TiC particles and primary TiC particles that are precipitated in situ from the liquid phase during solidification; 20% TiC coating indicates a large amount of TiC in the form of cross petals and twigs, and the figure points out that TiC exists like a large number of diffusely distributed spherical structures in the 30% TiC coating. The coatings of TiC/Co composite with less than 20% TiC showed good metallurgical bonding characteristics with the H13 steel surface.


Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 601 ◽  
Author(s):  
Tao Chen ◽  
Fan Wu ◽  
Haojun Wang ◽  
Defu Liu

To improve the wear resistance of titanium alloy parts used in the engineering applications, in-situ formed Ti(C,N) particles reinforcing Ni-based composite coatings are fabricated on Ti6Al4V alloys by the laser cladding technique using Ni60, C, TiN, and small amounts of CeO2 nanoparticles mixed powders as the pre-placed materials. Firstly, the formation mechanism of Ti(C,N) particles as a reinforced phase in the coating is investigated. Then, the influences of CeO2 nanoparticles on microstructures and wear resistance of the coatings are analyzed. It is indicated that the large Ti(C,N) particles form around TiN particles, and the small Ti(C,N) particles form through independent nucleation. CeO2 nanoparticles play important roles in increasing the nucleation rate and improving the precipitation of Ti(C,N), hence the microstructures and wear resistance of the coatings are apparently improved after adding CeO2 nanoparticles. It is observed that the 1 wt % content of CeO2 additive in the pre-placed powders is the best choice for the wear resistance of the coatings.


2010 ◽  
Vol 139-141 ◽  
pp. 398-401
Author(s):  
You Feng Zhang ◽  
Jun Li

In situ reaction synthesized TiB reinforced titanium matrix composites were fabricated using rapid non-equilibrium synthesis techniques of laser cladding. TiB/Ti composite coating was treated on Ti-6Al-4V surface using Ti and B powder mixture by laser cladding. Microstructure and dry sliding wear behavior of the in situ synthesized TiB/Ti composite coatings were investigated by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), energy-dispersive spectroscopy (EDS), hardness tester and friction and wear tester. The composite coatings consist of Ti, TiB and intermetallic compounds. The TiB reinforcement dispersed homogeneously in the composite coatings. The wear tests show that the friction coefficient and wear weight loss ratio of the coatings is lower than that of the Ti-6Al-4V alloy. The composite coating was reinforced by the in situ synthesized TiB ceramic particles. Based on the SEM observation, effects of scan speed on hardness and wear resistance of the laser cladding coatings were investigated and discussed.


2016 ◽  
Vol 23 (04) ◽  
pp. 1650019 ◽  
Author(s):  
K. L. QU ◽  
X. H. Wang ◽  
Z. K. Wang

In situ synthesized VC–VB particles reinforced Fe-based composite coatings were produced by laser beam melting mixture of ferrovanadium (Fe–V) alloy, boron carbide (B4C), CaF2 and Fe-based self-melting powders. The results showed that VB particles with black regular and irregular blocky shape and VC with black flower-like shape were uniformly distributed in the coatings. The type, amount, and size of the reinforcements were influenced by the content of FeV[Formula: see text]40 and B4C powders. Compared to the substrate, the hardness and wear resistance of the composite coatings were greatly improved.


2008 ◽  
Author(s):  
Ruiquan Kang ◽  
Mingxing Ma ◽  
Wenjin Liu ◽  
Minlin Zhong ◽  
Yide Kan ◽  
...  

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