Wear Resistance of Laser Treated Partially Stabilized Zirconia

1989 ◽  
Vol 111 (2) ◽  
pp. 372-377 ◽  
Author(s):  
V. Aronov ◽  
M. Benetatos
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Laser Beam ◽  
Laser Treatment ◽  
Surface Hardness ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia ◽  
Thermally Induced ◽  
Surface Polishing ◽  
Ceramic Surfaces

The laser beam treatment of magnesia partially stabilized zirconia (Mg-PSZ) sample surfaces has shown a considerable improvement in their wear resistance and surface hardness. The laser beam treated surfaces exhibited higher wear resistance than either ground untreated or ground and laser treated ceramic surfaces. There are optimum combination of the laser treatment process parameters (laser power and exposure characteristics) that resulted in the minimum wear rate or the maximum surface hardness. There was no correlation found between the wear rate and the surface hardness. There were two wear mechanisms operational, namely, surface fracture and surface polishing. The treatment of the ceramic surfaces reduced the fracture component of the wear rate. The laser treatment effect on the polishing process was not detected. The increase in the wear resistance and the surface hardness of the laser beam treated surfaces were due to the thermally induced phase transformations resulted in the formation of the compressive stress field on the surface and altering the surface structure.

Tribological Performance Study of HVOF-Sprayed Microstructured and Nanostructured WC-17wt.%Co Coatings

2010 ◽  
Author(s):  
Gobinda C. Saha ◽  
A. Mateen ◽  
Tahir I. Khan
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Oil Sands ◽  
Composite Coatings ◽  
Surface Hardness ◽  
Erosive Wear ◽  
Fusion Welding ◽  
Performance Study ◽  
Ductile Phase ◽  
The Core

Abrasive and erosive wear of components and machinery is an ongoing challenge in the oil sands industry in northern Alberta, Canada. To improve the wear resistance by increasing surface hardness of steels, heat treatments and deposition of hard layers of metal alloys (such as stellite) by fusion welding techniques are traditionally used. However, these deposition techniques are not applicable to all shapes and add considerable weight to the final component. Thermal spraying techniques such as the use of high velocity oxy-fuel (HVOF) composite coatings based on WC-Co cermet system offer better wear resistance and greater flexibility in applications. This study presents work on two feedstock powders, namely nanocrystalline and microcrystalline WC-Co cermets, with identical matrix phase content: WC-17wt.%Co. The novelty of the research is that an engineered duplex Co coated WC-17wt.%Co cermet particle designed to withstand coating spalling under elevated loads as well as to limit abrasive debridement during wear is introduced for the first time to produce a more homogeneously-dispersed coating microstructure. The engineered particle has 6wt.% of the ductile phase material mixed into the core to insure that the reinforcement WC phase is discontinuous to limit the debridement during wear, while remainder (11wt.%) of the Co is applied as a coating on the particle to improve the ductility. The mechanical properties of the overall particle are further improved by controlling the size of the reinforcing phase (WC) in the matrix (Co). This resulted in a WC-17wt.%Co particle containing a characteristic WC grain in the order of 350 nm in the core with the Co outer coating of 1–2 μm thick, making the powder particle as nanocrystalline. HVOF deposited coatings of the nanocrystalline and microcrystalline powders were examined for microhardness, fracture toughness, sliding abrasion (ASTM G133-05) and dry-sand rubber wheel abrasion (ASTM G65-04) wear performance. The wear rate under various loads and sliding distances was studied. In both the coatings, it was found that the wear rate increased with increasing applied loads, while it decreased with increasing sliding distances. 3D surface analysis of the wear tracks using atomic force microscopy (AFM) revealed two distinctive mechanisms associated with the two coatings after abrasive wear. The improved wear resistance was attributed to the higher hardness value of the nanostructured WC-17wt.%Co coating. It was also found that the nanostructured WC-17wt.%Co coating has about twice the toughness of the conventional microstructured coating counterpart. The extent of the WC decarburization and the dissolution of Co in the coatings were also studied.

scholarly journals Enhancement of the Wear Resistance and Microhardness of Aluminum Alloy by Nd:YaG Laser Treatment

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Haitham T. Hussein ◽  
Abdulhadi Kadhim ◽  
Ahmed A. Al-Amiery ◽  
Abdul Amir H. Kadhum ◽  
Abu Bakar Mohamad
Keyword(s):  
Wear Resistance ◽  
Aluminum Alloy ◽  
Wear Rate ◽  
Laser Treatment ◽  
Vickers Hardness ◽  
Nd:Yag Laser ◽  
Wear Behavior ◽  
X Ray ◽  
Before And After ◽  
Hardness Values

Influence of laser treatment on mechanical properties, wear resistance, and Vickers hardness of aluminum alloy was studied. The specimens were treated by using Nd:YaG laser of energy 780 mj, wavelength 512 nm, and duration time 8 ns. The wear behavior of the specimens was studied for all specimens before and after treatment by Nd:YaG laser and the dry wear experiments were carried out by sing pinon-disc technique. The specimens were machined as a disk with diameter of 25 mm and circular groove in depth of 3 mm. All specimens were conducted by scanning electron microscopy (SEM), energy-dispersive X-ray florescence analysis (EDS), optical microscopy, and Vickers hardness. The results showed that the dry wear rate was decreased after laser hardening and increased Vickers hardness values by ratio of 2.4 : 1. The results showed that the values of wear rate for samples having circular grooves are less than samples without grooves after laser treatment.

Friction Induced Strengthening Mechanisms of Magnesia Partially Stabilized Zirconia

1987 ◽  
Vol 109 (3) ◽  
pp. 531-536 ◽  
Author(s):  
V. Aronov
Keyword(s):  
Wear Resistance ◽  
Phase Transformation ◽  
Plastic Strain ◽  
Wear Behavior ◽  
Xrd Analysis ◽  
Stabilized Zirconia ◽  
Near Surface ◽  
Partially Stabilized Zirconia ◽  
Wear Rates ◽  
Frictional Interface

Experimental investigation of the wear behavior of Magnesia Partially Stabilized Zirconia (Mg-PSZ) rubbed against itself showed that up to three orders of magnitude increase in the wear resistance can be achieved in a particular temperature range that depends on both the sliding speed and the ambient temperature. XRD analysis revealed that thermally induced phase transformation takes place on the frictional interface. Surface analysis show that wear rates at maximum wear resistance are controlled by the crack generation kinetics rather than by crack propagation kinetics. The plastic strain before fracture varies with temperature. The maximum plastic strain was observed at the temperature of maximum wear resistance. A phenomenological model is presented that provides an explanation for the wear temperature behavior of Mg-PSZ. The model is based on the following chain of events that takes place on the frictional interface: spatial overheating of the surface areas, phase transformation of the overheated areas, cooling, volume expansion, and development of a compressive stress field in the near surface volumes.

Nitriding of Zirconia by Irradiation with NdrYAG Laser Beam

1995 ◽  
Vol 397 ◽  
Author(s):  
S. Fujitsu ◽  
M. Sawai ◽  
K. Kawamura ◽  
H. Hosono
Keyword(s):  
Laser Beam ◽  
Mass Spectroscopy ◽  
Nd:Yag Laser ◽  
Zirconium Nitride ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
Partially Stabilized Zirconia ◽  
X Ray ◽  
Secondary Ion

ABSTRACTThe surface of partially stabilized zirconia ceramics was irradiated by a Nd:YAG laser in various atmospheres. Zirconia strongly absorbed YAG's laser beam and changed its chemistry and microstructure. The change of color of zirconia into gold was due to the formation of zirconium nitride (ZrN) observed on the irradiated surface in air, nitrogen or ammonia, which was confirmed by X-ray diffraction and secondary ion mass spectroscopy. The observed ZrN phase was 10-20 um in thickness at the irradiated area by the direct beam. The adhesion between formed ZrN and YSZ substrate was very weak.

scholarly journals Microstructure and Wear-Resistant Properties of Ni80Al20-MoS2 Composite Coating on Sled Track Slippers

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 651
Author(s):  
Weihua Wang ◽  
Faqin Xie ◽  
Xiangqing Wu ◽  
Zheng Zhu ◽  
Shaoqing Wang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Composite Coating ◽  
Room Temperature ◽  
Surface Hardness ◽  
Wear Resistant ◽  
Lubrication Film ◽  
Coated Substrate ◽  
Volume Wear

In order to increase the surface hardness and wear-resistance property of sled track slippers, a Ni80Al20-MoS2 composite coating was fabricated on the surface of a stainless steel 0Cr18Ni9Ti sled track slipper via atmospheric spray and hot dipping. The microstructure, composition and surface hardness of coatings under different spraying powers were characterized and measured. The wear-resistant properties of the slipper substrate and the coating were also checked. The results showed that the higher the spraying power was, the greater the smoothness, density and hardness was of the Ni80Al20 coating, while the thickness initially increased and then decreased. When the spraying power was 18 kW, the thickness was 342.5 μm, the surface hardness was 304.1 Hv0.2, and the coating was composed of Ni, Al, Ni3Al, NiAl and a little Al2O3. The friction coefficient of the slipper substrate against GCr15 balls at room temperature in air was 0.7, while the coated substrate with MoS2 lubrication film was 0.3 and the volume wear rate declined by 1/5. The friction coefficient of the Ni80Al20 coating was 0.5 and the Ni80Al20-MoS2 composite coating was 0.15, while the volume wear rate declined by 1/4 and 1/3.

Nonlinear Wear Response of WC-Ni Cemented Carbides Irradiated by High-Intensity Pulsed Ion Beam

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
X. P. Zhu ◽  
F. G. Zhang ◽  
T. K. Song ◽  
M. K. Lei
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Abrasive Wear ◽  
High Intensity ◽  
Ion Beam ◽  
Surface Hardness ◽  
Specific Wear Rate ◽  
Cemented Carbides ◽  
Grain Fragmentation ◽  
Wear Response

Surface hardening on WC-Ni cemented carbides was achieved by high-intensity pulsed ion beam (HIPIB) irradiation, with formation of a binderless, densified, and “hilly” remelted top layer of a few μm in depth and a shock strengthened underlayer down to a hundred μm. The tribological behavior of the samples was studied under dry sliding against GCr15 bearing steel on a block-on-ring tribometer with 98 N and 0.47 m/s. The specific wear rate/wear resistance presented an exponential dependence on the surface hardness, in contrast to the commonly reported linear dependence of the specific wear rate or wear resistance on the hardness of WC based cemented carbides among both WC-Ni and WC-Co systems. The original samples underwent a severe abrasive wear due to the Ni binder micro-abrasion and WC grain fragmentation/pullout, whereas the irradiated samples began with a gradual abrasion of the binderless hard tops, followed by a mild abrasive wear accompanied by local adhesive wear. The wear resistance has been also compared with the reported data concerning the relative hardness of friction pairs in a value range of 2–7 on block-on-ring tribometer tests with the friction pairs of WC cemented carbides and steels in unlubricated condition. The nonlinear wear response is explained by the wear mechanism transition otherwise unobtainable in the case of the reported hardening by either lowering the binder content or refining the WC grains. It is revealed that the interfacial bonding enhancement of the WC/binder and the binder strengthening are pronounced for improving the wear resistance of the cemented carbides, by the effective suppressing of the WC grain fragmentation/pullout and binder micro-abrasion, even though they have limited contribution to the hardness enhancement.

DILLIDUR 450V

Alloy Digest ◽  
2011 ◽  
Vol 60 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
Wear Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Room Temperature ◽  
Surface Hardness ◽  
Heat Treating ◽  
Hot Working ◽  
Resistant Steel ◽  
Bend Strength

Abstract Dillidur 450V is a water hardened wear-resistant steel with surface hardness at room temperature of 420-480 HB. The steel is easy to weld and bend. Hot working is not recommended. This datasheet provides information on composition, physical properties, hardness, tensile properties, and bend strength as well as fracture toughness. It also includes information on wear resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-638. Producer or source: Dillinger Hütte GTS.

Sign in / Sign up

Export Citation Format

Share Document