scholarly journals Influence of Current on Wear Modes and Transition Condition of Current Collecting Materials

2019 ◽  
Vol 14 (2) ◽  
pp. 86-93 ◽  
Author(s):  
Chikara Yamashita ◽  
Koshi Adachi
Keyword(s):  
Transition Condition ◽  
Wear Modes

Reduction in Wear Rate of α-Alumina and Silicon Nitride by Diffusional Surface Modification

1988 ◽  
Vol 140 ◽  
Author(s):  
A.K. Gangopadhyay ◽  
M.E. Fine ◽  
H.S. Cheng
Keyword(s):  
Wear Resistance ◽  
Thermal Expansion ◽  
Surface Modification ◽  
Silicon Nitride ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Surface Region ◽  
Lattice Parameter ◽  
Lower Thermal Expansion ◽  
Wear Modes

AbstractThe surface regions of α-alumina and hot pressed silicon nitride were modified by suitable alloying in order to improve their wear resistance. The surface modification in polycrystalline α-alumina was done by diffusing chromia into the surface region which resulted in the formation of a thin layer of A12O3 - Cr9O3 solid solution which has a lower thermal expansion coefficient than pure α-alumina. Also Cr2O3 has a larger lattice parameter than α-alumina thus during cooling the surface was put into compression. The surface region of hot pressed silicon nitride was modified by diffusing α-alumina into the surface which resulted in the formation of a thin sialon layer. A surface compressive stress was again introduced due to the lower thermal expansion coefficient and larger latticeparameter of sialon compared to silicon nitride.Wear tests were conducted against 52100 steel under both lubricated and unlubricated sliding contact using a block on ring apparatus. The wear resistance of chromia surface alloyed α-alumina was improved considerably over unalloyed α-alumina under both lubricated and unlubricated conditions. The wear resistance of alumina surface alloyed silicon nitride was also improved over unalloyed silicon nitride under both lubricated and unlubricated conditions.Different wear modes were identified by examining the worn surfaces under the scanning electron microscope.

Experimental Study on Tool Wear when Machining Super Titanium Alloys: Ti6Al4V and Ti-555

2013 ◽  
Vol 763 ◽  
pp. 51-64
Author(s):  
Mohammed Nouari ◽  
Hamid Makich
Keyword(s):  
Tool Wear ◽  
Temperature Rise ◽  
Wear Behavior ◽  
Flow Direction ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Cutting Conditions ◽  
Wear Process ◽  
Texture Modification ◽  
Wear Modes

To understand the effect of the workpiece microstructure on the tool wear behavior, anexperimental investigation was conducted on machining two different microstructures of supertitanium alloys: Ti-6Al-4V and Ti-555. The analysis of tool-chip interface parameters such asfriction, heat flux and temperature rise and the evolution of the workpiece microstructure underdifferent cutting conditions have been discussed. As cutting speed and feed rate increase, the meancutting forces and temperature show different progressions depending on the consideredmicrostructure. Results show that wear modes for cutting tools used in machining the Ti-555 alloyshow contrast from those exhibited by tools used in machining the Ti6AI4V alloy. In fact, onlyabrasion wear was observed for cutting tools in the case of machining the near-β titanium Ti-555alloy. The last alloy is characterized by a fine-sized microstructure (order of 1 μm). For the usualTi6Al4V alloy, adhesion and diffusion modes followed by coating delamination process on the toolsubstrate have been clearly identified. Moreover, a deformed layer was observed under secondaryelectron microscope (SEM) from the sub-surface of the chip with β-grains orientation along thechip flow direction. The analysis of the microstructure confirms the intense deformation of themachined surface and shows a texture modification, without phase transformation. For the Ti-555β-alloy, β grains experiences more plastic deformation and increases the microhardness of theworkpiece inducing then an abrasion wear process for cemented carbide tools. For the Ti6Al4Vmicrostructure, the temperature rise induces a thermal softening process of the workpiece andgenerates adhesive wear modes for cutting tools. The observed worn tool surfaces confirm theeffect of the microstructure on tool wear under different cutting conditions for the two studiedtitanium alloys.

scholarly journals The effect of microstructure on wear modes of ceramic materials

Wear ◽  
1992 ◽  
Vol 154 (2) ◽  
pp. 371-385 ◽  
Author(s):  
O.O. Ajayi ◽  
K.C. Ludema
Keyword(s):  
Ceramic Materials ◽  
Wear Modes ◽  
Effect Of Microstructure

Detonation Sprayed Coatings and their Tribological Performances

2015 ◽  
pp. 294-327 ◽  
Author(s):  
D. Srinivasa Rao ◽  
G. Sivakumar ◽  
D. Sen ◽  
S.V. Joshi
Keyword(s):  
Wear Resistance ◽  
Erosive Wear ◽  
Spray Coating ◽  
Great Promise ◽  
Process Conditions ◽  
Comprehensive Overview ◽  
Cermet Coatings ◽  
Wear And Corrosion Resistance ◽  
Wear Modes ◽  
Sprayed Coatings

The Detonation Spray Coating (DSC) process is a unique variant among the wide choice of thermal spray processes. The typical functionalities of DSC coatings include wear and corrosion resistance, elevated temperature oxidation resistance, thermal barrier, insulative/conductive, abradable, lubricious surface, etc. Among the coatings for wear resistance, the cermet coatings based on WC–Co and Cr3C2–NiCr are the most popular materials of choice and contribute to bulk of the utilization by the industry towards wear resistance. Notwithstanding the above materials, alternative materials involving modifications in both hard and binder phases like TiMo (CN)–NiCo, WC-CrC-Ni, WC-Co-Cr, WC-Ni, Cr3C2-Ni, Cr3C2-Inconel, etc. exhibit great promise towards tribological applications under diverse wear modes. This chapter on the tribological characteristics of the detonation sprayed coatings provides a comprehensive overview on the characteristics of various cermet coatings generated at varied process conditions and its influence on the tribological properties under abrasive, sliding, and erosive wear modes.

scholarly journals Effect of Zr Target Current on the Mechanical and Tribological Performance of MoS2–Zr Composite Lubricating Coatings

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 80
Author(s):  
Wenlong Song ◽  
Zixiang Xia ◽  
Shoujun Wang ◽  
Qingge Zhang
Keyword(s):  
Mechanical Properties ◽  
Composite Coatings ◽  
Adhesive Force ◽  
Tribological Performance ◽  
Micro Hardness ◽  
Radio Frequency Magnetron Sputtering ◽  
Ion Plating ◽  
Surface Morphologies ◽  
Wear Modes ◽  
Mos2 Coating

To improve the tribological properties of pure MoS2 coating, the MoS2–Zr composite lubricating coatings were prepared on the WC/TiC/Co carbide surface utilizing radio frequency magnetron sputtering method combining with multiple arc ion plating technology. The effects of different Zr target currents on the surface morphologies, roughness, Zr content, adhesive force, thickness, microhardness and tribological behaviors of the composite coatings were systematically investigated. Results showed that the properties of MoS2 coating can be remarkably enhanced through co-deposition of a certain amount of Zr. As the Zr target current increased, the Zr content, surface roughness, thickness, and micro-hardness gradually increased, while the adhesive force of coatings increased first and then decreased. The friction behaviors and wear modes of the composite coatings both varied obviously with the increase of Zr current. The mechanism was mainly attributed to the different components and mechanical properties of the coatings caused by various Zr current.

Critical behavior of interfacial t-ZrO2 and other oxide features of zirconium alloy reaching critical transition condition

2021 ◽  
Vol 543 ◽  
pp. 152474
Author(s):  
Jingjing Liao ◽  
Junsong Zhang ◽  
Wei Zhang ◽  
Fei Xu ◽  
Zhongbo Yang ◽  
...  
Keyword(s):  
Critical Behavior ◽  
Zirconium Alloy ◽  
Critical Transition ◽  
Transition Condition
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