IMPROVING THE SURFACE PROPERTIES OF INCONEL 718 BY APPLYING A CO2 LASER HEAT TREATMENT TO A HIGH-VELOCITY OXY-FUEL COATING OF WC-CrCo POWDER

2010 ◽  
Vol 17 (02) ◽  
pp. 207-213 ◽  
Author(s):  
T. Y. CHO ◽  
J. H. YOON ◽  
Y. K. JOO ◽  
S. H. ZHANG ◽  
J. Y. CHO ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Surface Temperature ◽  
Surface Properties ◽  
High Velocity ◽  
Laser Heating ◽  
Sliding Wear ◽  
Surface Hardness ◽  
Wear Test ◽  
Wear Depth ◽  
Three Samples

A micron-sized WC-CrCo powder was coated onto an IN718 substrate using high-velocity oxy-fuel (HVOF) thermal spraying. To further improve the surface properties, the HVOF coating was heat-treated by a CO2 laser. The surface properties of both the coating and the laser-heated coating were then compared. The HVOF optimal coating process (OCP) for a coating with the highest surface hardness was determined with the Taguchi program. The friction and wear behaviors of the coating, an electrolytic hard chrome (EHC)-plated coating and IN718, were comparatively investigated via a reciprocating sliding wear test at both 25 and 450°C. The friction coefficient (FC) for all three samples decreased when the sliding surface temperature increased from 25 to 450°C. The FC of the coating decreased with increasing surface temperature: 0.33 ± 0.02 at 25°C to 0.26 ± 0.02 at 450°C; the coating had the lowest FC among the three samples. At both temperatures, the coating wear depth (WD) was smaller than those of the EHC sample and IN718. At room temperature, WC-CrCo and the EHC coatings had good wear resistance and had only a shallow WD. IN718, however, had poor wear resistance with 50 μm deep grooves created from fretting corrosion that arose during the 1500 reciprocating slides (2.5 Hz, 10 min sliding wear test). At 450°C, the coating WDs were much shallower than those for the EHC coating and IN718: 0.5-μm deep grooves compared to 60–70-μm deep grooves. These results proved that the coating provided a protective coating for IN718 and other metal components. With the OCP coating fabricated from the powders on the IN718 surface, the surface hardness increased 316% from 399 Hv to 1260 Hv. Furthermore, by laser heating the coating surface for 0.6 s, the hardness increased 44% from 1260 ±30 Hv to 1820 ±100 Hv, porosity decreased more than five times from 2.2 ± 0.3% to 0.4 ± 0.1%, and the coating thickness decreased 17% from 300 to 250 μm. These results showed that both the WC-CrCo powder coating and the laser-heating improved the surface properties of IN718.

Effects of sequential He+ and Ar+ implantation on surface properties of polymers

1996 ◽  
Vol 11 (10) ◽  
pp. 2661-2667 ◽  
Author(s):  
Gopal R. Rao ◽  
Eal H. Lee
Keyword(s):  
Wear Resistance ◽  
Surface Properties ◽  
Ion Irradiation ◽  
Surface Hardness ◽  
Wear Test ◽  
Surface Region ◽  
Near Surface ◽  
Ether Ether Ketone ◽  
Poly Ether Ether Ketone ◽  
Hardness Increase

Three important polymers: polystyrene (PS), poly ether ether ketone (PEEK), and polyimide Kapton, were irradiated separately with 1 MeV He+, 1 MeV Ar+, and 1 MeV He+ followed by 1 MeV Ar+ sequentially, to a fluence of 3 × 1019 ions/m2 for each ion. The specimens were characterized for changes in surface hardness using a nanoindentation technique, and wear resistance using a reciprocating sliding wear apparatus with a steel ball counterface. Results indicated that while all polymers showed higher hardness values after ion irradiation, the dual irradiation resulted in the largest hardness increase, greater than for the single ion-irradiated specimens. Wear test results also indicated that the dual He+ + Ar+ irradiation resulted in the best improvement in wear resistance of the polymers. These improvements in properties are a consequence of cross-linking of the polymer material caused by the ion irradiation. Linear energy transfer considerations showed that the dual He+ + Ar+ implantation was better because it combined a deeper implant, in the form of He, along with Ar irradiation which resulted in a shallower but more highly cross-linked layer at the near surface. Thus a deeper and graded cross-linked surface region was formed. The study shows that there is greater flexibility for tailoring surface properties of polymers by using a judicious combination of ion species, ion energies, and fluences.

Surface Modification by HVOF Coating of Micron-Sized WC-Metal Powder and Laser-Heating of the Coating

2011 ◽  
Vol 686 ◽  
pp. 654-660 ◽  
Author(s):  
Tong Yul Cho ◽  
Jae Hong Yoon ◽  
Sung Kang Hur ◽  
Hui Gon Chun ◽  
Shi Hong Zhang
Keyword(s):  
Metal Powder ◽  
Surface Properties ◽  
Laser Heating ◽  
Surface Hardness ◽  
Wear Depth ◽  
Hvof Spraying ◽  
Hvof Coating ◽  
Heat Treated ◽  
Deep Groove ◽  
Wear Tests

μWC-metal powder (powder) was coated onto the surface of Inconel 718 (IN718) using HVOF spraying for the improvement of surface properties. The coating was heat-treated by CO2(g) laser for further improvement of the properties. Optimal coating process was obtained from surface properties of 9 coatings prepared by Taguchi program. Surface property improvement by HVOF coating and laser-heating were investigated. The surface hardness of IN718 was increased by coating from 399 Hv to 1260±30 Hv, and further increased to 1860±100 Hv by laser-heating. Porosity of the coating was decreased by laser-heating from 2.2±0.3% to 0.4±0.1%. The friction coefficient of the surface was decreased by the coating from 0.48±0.06 to 0.33±0.02 at room temperature. Friction coefficients of IN718 and the coating were decreased with increasing sliding surface temperatures from 25°C to 450°C. According to reciprocating sliding wear tests, wear depth and trace of the coating were smaller than IN718 at both 25°C and 450°C. The coating had better wear resistance compared to IN718, creating smaller wear traces. At 450°C, wear depth of coating was much smaller than IN718: 50-µm-deep groove compared to 75 µm for IN718.

Microstructure and wear resistance of Cuss-toughened Cr5Si3/CrSi metal silicide alloys

2005 ◽  
Vol 20 (5) ◽  
pp. 1122-1130 ◽  
Author(s):  
Y.X. Yin ◽  
H.M. Wang
Keyword(s):  
Solid Solution ◽  
Wear Resistance ◽  
Sliding Wear ◽  
Room Temperature ◽  
Wear Test ◽  
Melting Process ◽  
Dry Sliding Wear ◽  
Metal Silicide ◽  
X Ray Diffraction ◽  
X Ray

Wear-resistant Cu-based solid-solution-toughened Cr5Si3/CrSi metal silicide alloy with a microstructure consisting of predominantly the dual-phase primary dendrites with a Cr5Si3 core encapsulated by CrSi phase and a small amount of interdendritic Cu-based solid solution (Cuss) was designed and fabricated by the laser melting process using Cr–Si–Cu elemental powder blends as the precursor materials. The microstructure of the Cuss-toughened Cr5Si3/CrSi metal silicide alloy was characterized by optical microscopy, powder x-ray diffraction, and energy dispersive spectroscopy. The Cuss-toughened silicide alloys have excellent wear resistance and low coefficient of friction under room temperature dry sliding wear test conditions with hardened 0.45% C carbon steel as the sliding–mating counterpart.

scholarly journals Impact-sliding wear response of 2.25Cr1Mo steel tubes: Experimental and semi-analytical method

Friction ◽  
2021 ◽  
Author(s):  
Meigui Yin ◽  
Chaise Thibaut ◽  
Liwen Wang ◽  
Daniel Nélias ◽  
Minhao Zhu ◽  
...  
Keyword(s):  
Sliding Wear ◽  
Power Plants ◽  
Mechanical Response ◽  
Wear Behavior ◽  
Wear Test ◽  
Steel Tube ◽  
Wear Depth ◽  
Sliding Velocity ◽  
Friction Forces ◽  
The Impact

AbstractThe impact-sliding wear behavior of steam generator tubes in nuclear power plants is complex owing to the dynamic nature of the mechanical response and self-induced tribological changes. In this study, the effects of impact and sliding velocity on the impact-sliding wear behavior of a 2.25Cr1Mo steel tube are investigated experimentally and numerically. In the experimental study, a wear test rig that can measure changes in the impact and friction forces as well as the compressive displacement over different wear cycles, both in real time, is designed. A semi-analytical model based on the Archard wear law and Hertz contact theory is used to predict wear. The results indicate that the impact dynamic effect by the impact velocity is more significant than that of the sliding velocity, and that both velocities affect the friction force and wear degree. The experimental results for the wear depth evolution agree well with the corresponding simulation predictions.

MICROSTRUCTURE AND DRY SLIDING WEAR RESISTANCE OF LASER CLADDING Ti-Al-Si COMPOSITE COATING

2017 ◽  
Vol 24 (Supp01) ◽  
pp. 1850009 ◽  
Author(s):  
H. X. ZHANG ◽  
H. J. YU ◽  
C. Z. CHEN ◽  
J. J. DAI
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Energy Dispersive Spectrometer ◽  
Wear Test ◽  
Dry Sliding Wear ◽  
Test Machine ◽  
Transmission Microscopy ◽  
Hardness Tester ◽  
Three Samples

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.

scholarly journals Effect of Cryogenic Treatment on Microstructure and Wear Resistance of Carburized 20CrNi2MoV Steel

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 808 ◽  
Author(s):  
Binzhou Li ◽  
Changsheng Li ◽  
Yu Wang ◽  
Xin Jin
Keyword(s):  
Electron Microscopy ◽  
Wear Resistance ◽  
Sliding Wear ◽  
Cryogenic Treatment ◽  
Wear Test ◽  
Deep Cryogenic Treatment ◽  
Transmission Electron ◽  
Conventional Heat Treatment ◽  
Carburizing Process ◽  
Ball On Disc

This paper investigated the response of carburized 20CrNi2MoV steel to cryogenic treatment including microstructure and wear resistance. Two cryogenic treatment methods including cryogenic treatment at −80 °C (CT) and deep cryogenic treatment at −196 °C (DCT) as well as conventional heat treatment (CHT) were carried out after carburizing process. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffractometry (XRD) were employed for microstructure characterization. The wear resistance was investigated by ball-on-disc sliding wear test on a multi-functional tribometer. The results show that the wear resistance of the experimental steel has been improved by 17% due to CT and by 25.5% due to DCT when compared to CHT. This significant improvement in wear resistance after cryogenic treatment is attributed to the microstructural changes including the finer martensitic structure, the reduction of retained austenite and the development of fine and more numerous carbides. Among these factors, the precipitation of fine carbides plays a more prominent role in enhancing wear resistance.

The Effect of Boron on the Sliding Wear Behavior of Iron-Based Hardfacing Alloys for Nuclear Power Plants Valves

2006 ◽  
Vol 510-511 ◽  
pp. 562-565
Author(s):  
Jeng Wan Yoo ◽  
Kwon Yeong Lee ◽  
Ji Hui Kim ◽  
Ki Soo Kim ◽  
Seon Jin Kim
Keyword(s):  
Wear Resistance ◽  
Martensitic Transformation ◽  
Nuclear Power ◽  
Sliding Wear ◽  
Power Plants ◽  
Wear Behavior ◽  
Wear Test ◽  
Wear Loss ◽  
The Matrix ◽  
Iron Based

A new iron-based wear resistance alloy was developed to replace the Co-containing Stellite 6 alloys in nuclear power industry. The effect of B addition on the wear resistance was investigated. Sliding wear tests of Fe-Cr-C-Si-xB (x = 0.0, 0.3, 0.6, 1.0 and 2.0 wt%) alloys were performed in air at the room temperature under a contact stress of 103 MPa. Low-boron alloys containing less than 0.6 wt% boron showed an excellent wear resistance than any other tested alloys. The improvement was associated with the matrix hardening by promotion of the γ→α′straininduced martensitic transformation occurring during the wear test. However, the alloys containing more than 1.0 wt% boron showed slightly increased wear loss compared to the low-boron alloys because of the absence of the strain-induced martensitic transformation and the presence of the brittle FeB particles, aiding crack initiation.

Investigation of thermochemical boriding effect on wear behavior of a GGG 50 quality as-cast ductile iron

2016 ◽  
Vol 68 (4) ◽  
pp. 476-481 ◽  
Author(s):  
Harun Mindivan
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Ductile Iron ◽  
Room Temperature ◽  
Wear Behavior ◽  
Surface Hardness ◽  
Wear Test ◽  
Content Type ◽  
Pin On Disc ◽  
Cast Ductile Iron

Purpose This study aims to investigate the microstructure and the abrasive wear features of the untreated and pack borided GGG 50 quality ductile iron under various working temperatures. Design/methodology/approach GGG 50 quality as-cast ductile iron samples were pack borided in Ekabor II powder at 900°C for 3 h, followed by furnace cooling. Structural characterization was made by optical microscopy. Mechanical characterization was made by hardness and pin-on-disc wear test. Pin-on-disc test was conducted on a 240-mesh Al2O3 abrasive paper at various temperatures in between 25 and 450°C. Findings Room temperature abrasive wear resistance of the borided ductile iron increased with an increase in its surface hardness. High-temperature abrasive wear resistances of the borided ductile iron linearly decreased with an increase in test temperature. However, the untreated ductile iron exhibited relatively high resistance to abrasion at a temperature of 150°C. Originality/value This study can be a practical reference and offers insight into the effects of boriding process on the increase of room temperature wear resistance. However, above 150°C, the untreated ductile iron exhibited similar abrasive wear performance as compared to the borided ductile iron.

scholarly journals “An Investigation of wear behavior of TiO2 nanoparticles mixed with Hybrid powder coating on MS material”

2021 ◽  
Vol 9 (12) ◽  
pp. 2350-2355
Author(s):  
Akshay Shinde
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Tio2 Nanoparticles ◽  
Sliding Wear ◽  
Wear Behavior ◽  
Wear Test ◽  
Powder Coating ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Maximum Contribution

Abstract: To improve the wear resistance of the hybrid powder coating, TiO2 nanoparticles was hot mixed to form a homogenous mixture with the powder in the range varying wt. dry sliding wear test conducted to determine the wear resistance. The experiments were design according to Taguchi L9 array to find the optimum nanoparticles content required to minimize the wear rate of the coating. ANOVA was used to determine the effect of the parameters on wear rate. It showed that reinforcement has the maximum contribution on the wear rate of the coating as compared to load and frequency. From the graph of means optimum parametric values was obtained at 2 % wt of reinforcement, 2 N load and 2 Hz frequency. The wear rate decrease with the increase in reinforcement. Keywords: Taguchi Method, Tribometer, Hybrid powder, TiO2, Wear Rate.

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