scholarly journals Surface modification of Ti alloys with WC-TiB2-reinforced laser composite coatings

2016 ◽  
Vol 23 (6) ◽  
pp. 737-741
Author(s):  
Jianing Li ◽  
Yuanbin Zhang ◽  
Hui Luo ◽  
Shuili Gong ◽  
Peng Li ◽  
...  

AbstractLaser cladding of the TiAl/Fe+Co-coated WC+TiB2 pre-placed mixed powders on a Ti-6Al-4V alloy substrate can be used to form TiB2/α-W2C-reinforced composite coating, which improved the wear resistance of the substrate. To further improve the TiB2/α-W2C-reinforced composite coating, yttria partially stabilized zirconia (YPSZ) was added into the pre-placed powders. A metallurgical bonding was formed between the YPSZ-infused composite coating and the substrate. Many amorphous alloys were produced in this composite coating due to the action of YPSZ, and such coating showed fine microstructure. Thus, it is feasible to further improve the wear resistance of the laser clad TiB2/α-W2C-reinforced composite coating through the addition of YPSZ.

2007 ◽  
Vol 280-283 ◽  
pp. 1489-1492
Author(s):  
Zhen Ting Wang ◽  
Hua Hui Chen

Micro-nanostructured WC composite coatings were successfully fabricated by induced heating sintering method on the surface of Q235 steel .The microstructure, micro-hardness and the wear resistance of the composite coatings were studied .The results show that the microstructure of induced heat layer is mainly composed of Ni-based solid solutions and WC particles. And there exists excellent metallurgical bonding between coating and substrate. The wear resistance of micro-nanostructured WC Composite Coatings is increased by 1.5 times on an average as compared with that of micron.


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 871 ◽  
pp. 134-143
Author(s):  
Yin Hua Shi ◽  
Qin Shi

γ-Fe/(Cr, Fe)7C3 lamellar eutectics reinforced the composite coating was deposited onto the 16Mn steel surface to enhance its surface hardness and wear resistance. The microstructure, phase composition, microhardness as well as wear resistance of the cladding coating were explored. Results indicated that the coating showed the dense and defect-free metallurgical bonding with the substrate and mainly consisted of (Cr, Fe)7C3, γ-Fe/(Cr, Fe)7C3 lamellar eutectic, B4C and carbon fibers. (Cr, Fe)7C3, B4C and carbon fibers were tightly embedded in the γ-Fe/(Cr, Fe)7C3 lamellar eutectics matrix. The microhardness and wear resistance of the coating compared with that of the substrate were highly improved by nearly 5 and 3 times, respectively.


2019 ◽  
Vol 26 (10) ◽  
pp. 1950077 ◽  
Author(s):  
H. X. ZHANG ◽  
J. J. DAI ◽  
Z. W. MA ◽  
X. Y. WANG ◽  
N. L. ZHANG

In this paper, TiC reinforced composite coatings were fabricated on TC4 alloy by laser cladding Ti,Al,Si, TiC and Y2O3 mixed powders. Microstructures and properties of the clad coatings with and without Y2O3 were discussed by comparative experiments. SEM, XRD and EDS were employed to discover the microstructures and the composition of phases. The hardness and wear resistance of the coatings were tested by the MM200 wear test machine and a HV-1000 digital hardness tester, respectively. The results showed that the coating was majorly composed of Ti5Si3, Ti7Al5[Formula: see text], Ti3AlC2, Ti3Al, Al3Ti, TiAl and Y2O3. The dilution zone exhibited a metallurgical bonding without pores and cracks. Compared with the TC4 substrate, the hardness and wear resistance of the coatings were heightened by 5–6 and 4.5–5.8 times, respectively. With 2.0[Formula: see text]wt.% Y2O3 addition, the microstructure of the coating was refined significantly, and the microhardness and dry sliding wear resistance were enhanced further. The effects of Y2O3 were attributed to heterogeneous nucleation of the residual Y2O3.


2017 ◽  
Vol 893 ◽  
pp. 340-344
Author(s):  
Sheng Dai ◽  
Dun Wen Zuo ◽  
Xian Rui Zhao ◽  
Jin Fang Wang

To improve the surface hardness and wear resistance of metal parts. Ni-based chromic carbidecomposite coating was prepared on the carbon steel (0.45 mass% C) substrates by laser cladding. Microstructure and wear properties of composite coatings were investigated by SEM, EDS, XRD, Vickers micro-hardness tester and wear machine. The results show that good metallurgical bonding between the Ni-based chromic carbidecomposite coating and carbon steel substrate. Micro-hardness of Ni-based Cr3C2 composite coating along the layer depth presents an evident stepladder distribution. The average micro-hardness of the laser clad coating is about 950 HV. The result of wear experiment shows that Ni-based Cr3C2 composite coating processes good wear resistance.


2013 ◽  
Vol 20 (4) ◽  
pp. 307-310
Author(s):  
Li Wei

AbstractA hard SiC-B4C reinforced composite coating was fabricated by laser alloying of SiC-B4C+Al-Sn-Mo-Y2O3 mixed powders on a Ti-3Al-2V alloy. Al-Sn-Mo mixed powders were first used in the laser alloying technique to improve the wear resistance of titanium alloys. Proper selection of the laser alloying process parameters allows us to obtain a composite coating with a metallurgical combination with substrate. Under the action of Mo, fine particles with high microhardness were produced in the coating matrix and also hindered the formation of adhesion patches and deep plowing grooves during the sliding wear process, leading to the improvement of wear resistance of a titanium alloy substrate surface.


2021 ◽  
Author(s):  
Linlin ZHANG ◽  
Dawei ZHANG

Ni-Co-W composite coatings modified by different contents of Co-based alloy powder in the Ni-based alloy with 35 wt.% WC (Ni35WC) were deposited on stainless steel by laser cladding. The influence of compositional and microstructural modification on the wear properties has been comparatively investigated by XRD, SEM, and EDS techniques. It was found that the austenite dendrites in the modified coating adding 50 wt.% Co-based alloy were refined and a lot of Cr23C6 or M23(C, B)6 compounds with fine lamellar feature were formed around austenitic grain boundaries or in the intergranular regions. The contribution of element Co to the modification of Ni35WC coating is that it cannot only promote the formation of more hard compounds to refine austenite grains, but also refine the size of precipitates, and change the phase type of eutectic structure as a result of disappeared Cr boride brittle phases. A noticeable improvement in wear resistance is obtained in the Ni35WC coating with 50 wt.% Co-based alloy, which makes the wear rate decreased by about 53 % and 30% by comparison to that of the substrate and the Ni35WC coating, respectively. It is suggested that the improvement is closely related to the composite coating being strengthened owing to the increase of coating hardness, formation of a fine-grained microstructure caused by Co, and fine hard precipitate phases in the eutectic structure.


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.


2017 ◽  
Vol 62 (4) ◽  
pp. 2421-2424 ◽  
Author(s):  
N. Gidikova ◽  
M. Sulowski ◽  
V. Petkov ◽  
R. Valov ◽  
G. Cempura

AbstractChrome plating is used to improve the properties of metal surfaces like hardness, corrosion resistance and wear resistance in machine building. To further improve these properties, an electrodeposited chromium coating on steel, modified with nanodiamond particles is proposed. The nanodiamond particles (average size 4 nm measured by TEM) are produced by detonation synthesis (NDDS). The composite coating (Cr+NDDS) has an increased thickness, about two times greater microhardness and finer micro-structure compared to that of unmodified chromium coating obtained under the same galvanization conditions. In the microstructure of specimen obtained from chrome electrolyte with concentration of NDDS 25 g/l or more, “minisections” with chromium shell were found. They were identified by metallographic microscope and X-ray analyser on etched section of chromium plated sample. The object of further research is the dependence of the presence of NDDS in the composite coating from the nanodiamond particles concentration in the chroming electrolyte.


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