Effect of Al2O3 Xerogel on the Microstructure and the Properties of Laser Cladding Coating of Fe-Based Alloy

2010 ◽  
Vol 434-435 ◽  
pp. 743-746
Author(s):  
Shi Hai Zhao ◽  
Xiu Ming Jiang ◽  
Xu Guo Huai ◽  
Xiao Wei Fan

Laser cladding Fe-based alloy coatings with 0, 3, 6, 9, 12 and 15% Al2O3 xerogel on 45 steel substrates were prepared by 5kWCO2 continuous wave laser. The effect of the content of Al2O3 xerogel on the microstructure, microhardness and wear resistance of the coatings was investigated by scan electron microscope, X-ray diffraction. The results show that the microstructure and properties were different when the content of Al2O3 xerogel changed. The addition of Al2O3 xerogel can enhance the fluidity of molten liquid and refine the microstructure. Adding adequate amount of Al2O3 xerogel to Fe-based alloy can improve the hardness and the wear resistance due to the nano-Al2O3 particles on surfaces and the dispersion strengthening and hardening of nano- Al2O3 particles.

2010 ◽  
Vol 44-47 ◽  
pp. 4157-4161
Author(s):  
Fan Zhi Kong ◽  
Xiao Dong Hu ◽  
Jian Hua Yao ◽  
Cheng Hua Lou

High power continuous wave (CW) CO2 laser cladding was performed on H13 steel, pre-coated by superfine WC. After laser cladding, the materials were tempered for 6 hours. Scanning electronic microscopy (SEM) was used to observe the morphologies of the cladding layer. X-ray diffraction (XRD) was employed to analyze the microstructure of the cladding layer. The changes of microhardness, temper resistance and wear resistance were tested. The microhardness of cladding layer before tempering was 1.4 times of that of base metal and 1.9 times after tempering at 500°C. The wear resistance and tempering resistance were improved.


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.


2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Meiyan Li ◽  
Bin Han ◽  
Conghua Qi ◽  
Yong Wang ◽  
Lixin Song

The composite processing between laser cladding and low temperature (300°C) ion sulfurization was applied to prepare wear resistant and self-lubricating coating. The microstructure, morphology, phase composition, valence states, and wear resistance of the composite coating were investigated by scanning electron microscopy (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscope (XPS), and friction and wear apparatus. The results indicate that the laser cladding Ni-based coatings and the maximum hardness of 46.5 HRC were obtained when the percent of pure W powder was 10%, composed of columnar dendrites crystals and ultrafine dendritic structure. After ion sulfurization at 300°C for 4 h, the loose and porous composite coating is formed with nanograins and the granularity of all grains is less than 100 nm, which consists ofγ-(Fe, Ni), M23C6carbides, FeS, FeS2, and WS2. Furthermore, the wear resistance of the composite coating is better than the laser cladding Ni55 + 10%W coating, and the friction coefficient and mass losses under the conditions of dry and oil lubrication are lower than those of laser cladding Ni55 + 10%W coating.


2011 ◽  
Vol 18 (03n04) ◽  
pp. 103-108 ◽  
Author(s):  
JIANING LI ◽  
CHUANZHONG CHEN ◽  
CUIFANG ZHANG

Laser cladding of the Fe3Al + B4C/TiN + Al2O3 pre-placed powders on the Ti-6Al-4V alloy can form the Ti3Al/Fe3Al + TiN/TiB2 composite coating, which improved the wear resistance of the Ti-6Al-4V alloy surface. In this study, the Ti3Al/Fe3Al + TiN/TiB2 composite coating has been researched by means of X-ray diffraction and scanning electron microscope. It was found that during the laser cladding process, Al2O3 can react with TiB2 , leading to the formations of Ti3Al and B . This principle can be used to improve the Fe3Al + B4C/TiN laser-cladded coating on the Ti-6Al-4V alloy. Furthermore, during the cladding process, C consumed the oxygen in Fe3Al + B4C /TiN + Al2O3 molten pool, which retarded the productions of the redundant metal oxides.


2019 ◽  
Vol 26 (06) ◽  
pp. 1850207 ◽  
Author(s):  
XUELONG PING ◽  
SHUTING SUN ◽  
FENG WANG ◽  
HANGUANG FU ◽  
JIAN LIN ◽  
...  

In this paper, the enhancement of NiCrBSi coatings by adding Cr3C2 were investigated. The NiCrBSi coatings with different additions of Cr3C2 were produced by laser cladding. The microstructure, hardness and wear resistance of the coatings were studied by optical microscope (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), microhardness tester and M-200 wear tester. It is found that the main phases in the coatings are [Formula: see text]-Ni, Cr[Formula: see text]C6 and Cr7C3, and they also contain a small amount of CrB, Ni4B3 and Ni3Si2. Moreover, with the increase of Cr3C2 addition, the microhardness and wear resistance of coatings are obviously improved. When the addition of Cr3C2 is 20%, the wear resistance of the coating is the best, and the wear resistance of the coating increased by 191.2% than that of the Cr3C2-free coating. The wear resistance of coating decreases when the addition of Cr3C2 reaches 30%.


Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1279 ◽  
Author(s):  
Xiangchun Hou ◽  
Dong Du ◽  
Baohua Chang ◽  
Ninshu Ma

Fe-based amorphous alloys with excellent mechanical properties are suitable for preparing wear resistant coatings by laser cladding. In this study, a novel Fe-based amorphous coating was prepared by laser cladding on 3Cr13 stainless steel substrates. The influence of scanning speeds on the microstructures and properties of the coatings was investigated. The microstructure compositions and phases were analyzed by scanning electron microscope, electron probe microanalyzer, and x-ray diffraction respectively. Results showed that the microstructures of the coatings changed significantly with the increase of scanning speeds. For a scanning speed of 6 mm/s, the cladding layer was a mixture of amorphous and crystalline regions. For a scanning speed of 8 mm/s, the cladding layer was mainly composed of block grain structures. For a scanning speed of 10 mm/s, the cladding layer was composed entirely of dendrites. Different dilution rates at the bonding zones were the main reasons for the microstructure change for different claddings. For all three scanning speeds, the coatings had higher hardness and wear resistance when compared with the substrate; as the scanning speed increased, the hardness and wear resistance of the coatings gradually decreased due to the change in microstructure.


2018 ◽  
Vol 913 ◽  
pp. 390-395
Author(s):  
Yong Tian Wang ◽  
Jia Wei Mo ◽  
Lu Lu Tao

A large thick Fe based amorphous composite coating was deposited on the carbon steel substrate by laser cladding method. The phase composition and microstructure are characterized using X-ray diffraction and scanning electron microscope, respectively. The results demonstrate that the large thick laser cladding coating has a typical layered structure mainly consisting of amorphous and nanocrystal phases. The wear resistance and microhardness property are tested by the Vickers hardness tester and MLS-225 type wet sand rubber wheel abrasion tester. The results show that the large thick laser cladding coating has excellent wear resistance and hardness.


2008 ◽  
Vol 368-372 ◽  
pp. 398-401 ◽  
Author(s):  
You Na Wu ◽  
Chang Hua Cheng ◽  
Zhao Xian Xiong

Hexagonal NaYF4:Ln3+ (Ln3+=Yb3+ and Tm3+) was prepared via solid-state synthesis route. The synthesized powders were identified with X-ray diffraction patterns. Hexagonal phase was obtained by heating the powders at 550°C in reducing atmosphere, and the ions of Yb3+ and Tm3+ were completely incorporated into the lattice of hexagonal NaYF4 in the doping concentration range. Microstructure of the phosphor was observed by scanning electron microscopy (SEM). Intense blue (1G4→3H6, 1D2→3F4) and weak red (1G4→3F4) upconversion emission of Tm3+ ions with the energy transferred from Yb3+ ions were observed in the phosphor excited with a 980nm continuous wave laser diode. The intensity of blue emission was effectively enhanced by suitable doping of Tm3+ and Yb3+ ions, and strongest blue emission was obtained with the concentration of 0.2mol% Tm3+ and 40mol% Yb3+ doped.


2011 ◽  
Vol 80-81 ◽  
pp. 60-63
Author(s):  
Xue Qing Yue ◽  
Hua Wang ◽  
Shu Ying Wang

Incorporation of metallic elements, titanium and copper, into carbonaceous mesophase (CM) was performed through mechanical alloying in a ball mill apparatus. The structures of the raw CM as well as the Ti/Cu-added CM were characterized by X-ray diffraction. The tribological behavior of the Ti/Cu-added CM used as lubricating additives was investigated by using a high temperature friction and wear tester. The results show that, compared with the raw CM, the Ti/Cu-added CM exhibits a drop in the crystallinity and a transition to the amorphous. The Ti/Cu-added CM used as lubricating additive displays an obvious high temperature anti-friction and wear resistance effect, and the lager the applied load, the lower the friction coefficient and the wear severity.


2008 ◽  
Vol 373-374 ◽  
pp. 304-307
Author(s):  
Sen Yang ◽  
Ming Run Wang ◽  
Tao Gong ◽  
Wen Jin Liu

In order to improve wear resistance of carbon steel, laser cladding experiments were carried out using a 3kW continuous wave CO2 laser. The diameter of the laser beam was 3-5mm, the scanning velocity was 3-10mm/s, and the laser output power was 1.0-1.3kW. The experimental results showed that MoSi2/SiCP composites coating could be in-situ synthesized from mixture powders of molybdenum, silicon and SiC by laser cladding. A good metallurgical bond between the coating and the substrate could be achieved. The microstructures of the coating were mainly composed of MoSi2, SiC and FeSiMo phases. The average microhardness of the coating was about HV0.21300, about 6.0 times larger than that of steel substrate.


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