Improvement in Wear Resistance of Nano WC-Co Coatings Fabricated by Detonation Gun Spraying

2007 ◽  
Vol 539-543 ◽  
pp. 1264-1269
Author(s):  
S.Y. Park ◽  
Moon Chul Kim ◽  
Chan Gyung Park
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Wear Resistance ◽  
Amorphous Phase ◽  
Phase Decomposition ◽  
Post Heat Treatment ◽  
Detonation Gun Spraying ◽  
Carbide Phases ◽  
Carbide Size ◽  
Detonation Gun

Nano structured WC-Co coatings with carbide size of 100−200nm were fabricated by detonation gun spraying. The fabricated nano coatings showed improved hardness and wear resistance compared to micron WC-Co coatings. Considerable phase decomposition of WC to W2C and amorphous phase in nano coatings was detected, which is known to degrade wear resistance of coatings. In order to improve the wear resistance of the coatings by recovering of dissociated carbide phases, post heat treatment was conducted in Ar environment at temperature range of 400−900°C. Harness, fracture toughness and wear resistance of nano coatings were significantly improved by post heat treatment. The improved properties were elucidated and discussed in terms of microstructure and phase compositions.

scholarly journals EFFECT OF HEAT TREATMENT ON THE MICROSTRUCTURE AND PERFORMANCE OF HIGH-VELOCITY AIR-FUEL SPRAYED WC-10Co4Cr COATINGS

2021 ◽  
Vol 55 (6) ◽  
Author(s):  
Yong Xue ◽  
Xuedong Zhou ◽  
Haijun Liu ◽  
Jishi Zhang ◽  
Jinsheng Ji ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
Amorphous Phase ◽  
High Velocity ◽  
Wear Test ◽  
Treatment Temperature ◽  
Heat Treated ◽  
Original Coating

In this study a high-velocity air-fuel (HVAF) flame-sprayed WC-10Co4Cr coating was heat-treated at (240; 300; 400) °C for 2 h in an air atmosphere. The effect of the heat treatment on the hardness, fracture toughness, wear resistance, corrosion resistance, phase composition and microstructure behaviour of the coatings was investigated. It could be concluded from the X-ray diffraction (XRD) pattern that the phase of the coatings was mainly composed of tungsten carbide, an amorphous phase, a small amount of W2C and trace metal tungsten. However, the heat-treated coating had a small increase in W2C compared to the original coating, although the amount of amorphous phase did not decrease significantly. The results indicated that as the heat-treatment temperature increased, the hardness of the coating first increased and then decreased, while the fracture toughness increased. The polarization test confirmed that the heat-treated coating had higher corrosion resistance than the original coating. In addition, the results of the reciprocating friction and wear test indicated that small amounts of W2C strengthening phases were formed in the WC-10Co4Cr coating after heat treatment at 400 °C. This process did not eliminate many of the tougher Co and WC phases. Therefore, this coating had the best wear resistance among all the comparative coatings.

scholarly journals Microstructures and Mechanical Properties of Deposited Fe-8Cr-3V-2Mo-2W on SCM420 Substrate Using Directed Energy Deposition and Effect of Post- Heat Treatment

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1231
Author(s):  
Ye Eun Jeong ◽  
Jun Yeop Lee ◽  
Eun Kyung Lee ◽  
Do Sik Shim
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Wear Resistance ◽  
Energy Deposition ◽  
Surface Hardness ◽  
Steel Powder ◽  
Post Heat Treatment ◽  
Directed Energy

In this study, the Fe-8Cr-3V-2Mo-2W tool steel powder was deposited on the SCM420 substrate through the directed energy deposition (DED) process. This study focuses on the mechanical properties of the deposited Fe-8Cr-3V-2Mo-2W and the effect of heat treatment on it. The changes in the microstructural characteristics of the deposited region due to heat treatment after deposition were observed. The influence of heat treatment on the mechanical properties was then analyzed accordingly and hence, the hardness, wear, impact and tensile tests were conducted on the deposited material. These properties were compared with those of the commercial tool steel powder M2-deposited material and the carburized specimen. In the deposited Fe-8Cr-3V-2Mo-2W layer, an increased martensite phase fraction was obtained through post-heat treatment and the amount of precipitated carbides was also increased. This increased the hardness from 48 to 62 HRc after heat treatment and the wear resistance was significantly improved as well. The amount of impact energy absorbed decreased from 11 J before heat treatment to 6 J after heat treatment, but the tensile strength significantly increased from 607 to 922 MPa. When compared with the M2-deposited surface, the Fe-8Cr-3V-2Mo-2W deposits had 3% lower surface hardness and 76% lower fracture toughness but exhibited 56% higher tensile strength. When compared with the carburized SCM420, the Fe-8Cr-3V-2Mo-2W deposits exhibited 3% higher surface hardness and wear resistance, 90% lower fracture toughness and 5% higher tensile strength. This study shows that surface hardening through DED can exhibit similar or superior mechanical properties when compared to carburizing.

DEWARD

Alloy Digest ◽  
1976 ◽  
Vol 25 (12) ◽  
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Wear Resistance ◽  
Compressive Strength ◽  
Physical Properties ◽  
Heat Treating ◽  
Die Steel ◽  
Satisfactory Performance ◽  
Specialty Steel ◽  
Minimum Distortion

Abstract DEWARD is an oil-hardening, non-deforming, manganese die steel that is characterized by uniformity, good machinability and satisfactory performance in service. Its composition permits a relatively low hardening temperature to give minimum distortion after heat treatment and little danger of cracking. It has good wear resistance and gives excellent results when used for all kinds of intricate tools. This datasheet provides information on composition, physical properties, hardness, elasticity, and compressive strength as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: TS-310. Producer or source: AL Tech Specialty Steel Corporation.

scholarly journals Effect of heat treatment on the microstructure, hardness and abrasive wear resistance of high chromium hardfacing

2013 ◽  
Vol 59 (No. 1) ◽  
pp. 23-28 ◽  
Author(s):  
R. Chotěborský
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Wear Resistance ◽  
Abrasive Wear ◽  
Abrasive Wear Resistance ◽  
Air Cooling ◽  
High Chromium ◽  
Secondary Carbides ◽  
Cooling Conditions ◽  
Dendritic Austenite

The effect of destabilization heat treatment on the microstructure, hardness, fracture toughness and abrasive wear resistance of high chromium hardfacing was investigated. The results from the study shows that the hardness, frac­ture toughness and abrasive wear resistance are influenced by temperature of destabilization heat treatment and air and furnace cooling conditions, respectively. Destabilization treatment of materials by furnace cooling caused higher secondary carbides in the dendritic austenite whilst by air cooling it showed smaller particles of secondary carbide. Also, it was found that destabilization temperature at 1,000°C improves hardness compared with hardfacing after weld depositing. The study, however, indicated that Palmqvist fracture toughness method is a useful technique for measuring the fracture toughness of high chromium hardfacing compared to Vicker’s hardness method.    

Influence of Heat Treatment on Fracture Toughness and Wear Resistance of Nicral-Zro2 Multilayered Thermal Barrier Coating

2018 ◽  
Vol 37 (5) ◽  
pp. 463-475
Author(s):  
Zibo Ye ◽  
Guanghong Wang
Keyword(s):  
Heat Treatment ◽  
Fracture Toughness ◽  
Wear Resistance ◽  
Xrd Analysis ◽  
Thermal Barrier ◽  
Homogeneous Microstructure ◽  
Barrier Coating ◽  
Before And After ◽  
T Phase ◽  
The Relationship

AbstractThe chemical composition and fracture toughness of thermal barrier coatings (TBCs) before and after heat treatment were characterized, and the cracks around the interface between the coating and the substrate could be successfully eliminated and meanwhile the porosity of the coatings tended to reduce. The XRD analysis revealed the coatings were composed of non-transformable tetragonal t’ phase of ZrO2 and $\gamma $-(Ni, Cr) with minor Ni3Al ($\gamma ^' $) precipitates. Additionally, the relationship between the heat treatment and wear resistance was systematically studied. The results indicated that both the hardness and fracture toughness increased after quenching process. The oxidation wear became more prominent after heat treatment, which probably resulted from the better bonding strength of coatings. Dense and homogeneous microstructure introduced by vacuum oil-quenching improved stabilization of the weight gain during thermal cycle test.

TOUGHMET 2

Alloy Digest ◽  
2013 ◽  
Vol 62 (5) ◽  
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Fracture Toughness ◽  
Wear Resistance ◽  
High Performance ◽  
Mechanical Performance ◽  
High Thermal Stability ◽  
Lead Free ◽  
Plain Bearing ◽  
Ni Alloy

Abstract ToughMet 2 is a high performance, wrought, heat treatable, lead-free strip Cu-Ni alloy that imparts superior mechanical performance and high thermal stability to plain bearing applications. Parts are easily formed and they can be machined either before or after heat treatment. ToughMet alloys are a line of spinodal hardened Cu-Ni anti-galling alloys for bearings capable of performing with a variety of shafting materials and lubricants. The alloys combine a high lubricity with wear resistance in these severe loading conditions. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as forming and machining. Filing Code: Cu-724. Producer or source: Materion Brush Performance Alloys. Originally published September 2004, revised May 2013.

Effect of carbides on the wear resistance of white cast iron alloyed with 12.7 wt.-% Cr and nickel

2020 ◽  
Vol 62 (8) ◽  
pp. 788-792
Author(s):  
Tanju Teker ◽  
S. Osman Yilmaz ◽  
Tekirdağ Teker
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Cast Iron ◽  
White Cast Iron ◽  
Volume Fraction ◽  
High Wear Resistance ◽  
Homogeneous Distribution ◽  
Nickel Concentration ◽  
Carbide Size ◽  
Wear Tests

Abstract White cast iron with about 12.7 wt.-% chromium was alloyed with Ni, W and Mo for heat treatment applications. Heat treatments were performed at a range of 850-1050 °C for 1 h in order to distribute M7C3 carbides homogeneously in an environment of high wear resistance. The contents of the C, Cr, Ni, Mo, Mn and Si elements selected for the alloys were similar, though a 6 wt.-% nickel concentration was chosen. Microstructural changes in the specimens were examined by scanning electron microscopy (SEM) and optical microscopy (OM). Macro-hardness, average carbide size and volume fraction were analyzed. Wear tests were carried out under different loads of 10, 20 and 30 N. It was seen that heat treatment changed the carbide size and homogeneous distribution of the carbides. Moreover, the addition of nickel to HCrWCI increased fracture toughness and reduced the wear rate.

Microstructural and Mechanical Properties Changes of Silicon Nitride Based Ceramic Using Post-Sintering Heat Treatment

2012 ◽  
Vol 727-728 ◽  
pp. 1085-1091
Author(s):  
José Vitor C. Souza ◽  
O.M.M. Silva ◽  
E.A. Raymundo ◽  
João Paulo Barros Machado
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Fracture Toughness ◽  
Grain Size ◽  
Wear Resistance ◽  
High Hardness ◽  
Gas Pressure ◽  
Low Density ◽  
Nitrogen Gas ◽  
Structural Applications

Si3N4based ceramics are widely researched because of their low density, high hardness, toughness and wear resistance. Post-sintering heat treatments can enhance their properties. Thus, the objective of the present paper was the development of a Si3N4based ceramic, suitable for structural applications, by sintering in nitrogen gas pressure, using AlN, Al2O3, and Y2O3as additives and post-sintering heat treatment. The green bodies were fabricated by uniaxial pressing at 80 MPa with subsequent isostatic pressing at 300 MPa. The samples were sintered at 1900°C for 1 h under N2gas pressure of 0.1 MPa. Post-sintering heat treatment was performed at 1500°C for 48 h under N2gas pressure of 1.0 MPa. From the results, it was observed that after post-sintering heat treatment there was a reduction of α-SiAlON phase and increase of β-Si3N4phase, with consequent changing in grain size, decrease of fracture toughness and increase of the Vickers hardness.

Sign in / Sign up

Export Citation Format

Share Document