Tribological Analysis of Thermal Spray Coatings of Ni and Al2O3 With Dispersion of Solid Lubricants in Wear Modes

2017 ◽  
Author(s):  
John V. Christy ◽  
Abdel-Hamid I. Mourad ◽  
Sudhir Tiwari
Keyword(s):  
Thermal Spray ◽  
Cutting Tool ◽  
Elevated Temperatures ◽  
Erosive Wear ◽  
Solid Lubricants ◽  
Pressure Vessels ◽  
Work Piece ◽  
Separate Analysis ◽  
Permeable Membrane ◽  
Wear Modes

In the present work, Ni and 60 wt. % of Al2O3, as thermal spray was mixed in 2:1 proportion with entrapped solid lubricant such as PTFE and Graphite through a D-Gun on the Bakelite used as substrate. For that, the specimen was taken and cleaned properly and coated with thermal spray and solid lubricating coatings of 0.5 micrometre thickness. At elevated temperatures, NiAl2O3 a common thermal spray coating protects the solid lubricants entrapped in it and thus causes the layer to be stable and dynamic. The solid lubricants mixed in thermal spray were graphite and PTFE. These were then ultrasonically cleaned in the acetone bath. The coating is done by a duo spray pump that spurts the coating on the work piece. This pump spurting is controlled by a semi permeable membrane coated on the work piece. Coatings were tested at different air pressure, temperature and impingement angle. It was found that the degradation of coating was observed on low impingment angles and also with the reciprocating stress inputs. The Graphite and NiAl2O3 coating is found to be more stable tribologically as compared to PTFE and NiAl2O3 coating at high temperatures and pressures. Morphological analysis of coatings was also done. The coating was tested on cutting tool ends like drill bits, planar cutting tool and turning tools. Separate analysis was carried out on erosive wear, abrasive wear, temperature and pressure with varied load conditions on the coatings done on Bakelite. On all the individual tests done Graphite and NiAl2O3 mix coating was found stable. This coating finds much more application in pipes and pressure vessels systems. The inside bore of a pipe can be coated similarly which will smoothly transfer the abrasive sludge or fluids with much reduction on its friction coefficient.

Simulation of Thermal Spray Process Based on Particle Tracing Method

2000 ◽  
Author(s):  
K. Wada ◽  
M. Ito ◽  
M. Takahashi ◽  
K. Takaishi
Keyword(s):  
Thermal Spray ◽  
Coating Thickness ◽  
Computer Aided Design ◽  
Simulation Method ◽  
Work Piece ◽  
Stainless Steel 316L ◽  
Particle Tracing ◽  
Computer Aided ◽  
Thermal Spray Processes ◽  
Tracing Method

Abstract As applications of thermal spray processes are expanding, the importance of computer-aided design systems and computer-aided engineering systems for these processes has been growing. The principal objective of this study is to propose a new analytic method for the prediction of coating thickness and deposition efficiency. This method is called the particle tracing method and is based on the Monte Carlo simulation method. In order to evaluate the validity of this model, several tests were carried out. The same stainless steel 316L layers coated by the HP/HVOF process (TAFA JP-5000) were used throughout each test. First, spray patterns were observed which had formed on flat-plate specimens from various spray gun angles. Coating thickness distributions on several curved planes were consequently investigated. Finally, the coating process for a blade of a compressor in a gas turbine was simulated. In the right of the results of these experiments, it is summarized that the calculated values of the coating thickness obtained by our method are in good agreement with experimental values. The accuracy is within 10% of the maximum thickness value in each specimen, except for at the edge of the work-piece. In conclusion, the particle-tracing method can be applied to the fundamental analytic model in the CAD or CAE system for thermal spray processes.

scholarly journals Dispositivos De Interrupcion Subia (Dis) Para El Analisis De Raices Viruta

2014 ◽  
Vol 2 (2) ◽  
Author(s):  
Diego Alejandro Neira Moreno
Keyword(s):  
Cutting Tool ◽  
Cutting Tools ◽  
Scientific Research ◽  
Cutting Process ◽  
Work Piece ◽  
Mechanical Forces ◽  
Machining Processes ◽  
Research Instrument ◽  
Machined Parts ◽  
Interaction Phenomena

El estudio de las variables y efectos derivados del mecanizado provee herramientas de conocimiento tendientes a optimizar el uso de las herramientas y los procedimientos de maquinado industrial. Este artículo de reflexión aborda el uso de los dispositivos de interrupción súbita (DIS) como herramientas de obtención de raíces de viruta para la investigación científica del mecanizado industrial, y para el estudio de los efectos derivados de la interacción entre las herramientas de corte y el material de trabajo, en función de los cambios microestructurales del material de trabajo, dependientes de la temperatura producida y los esfuerzos mecánicos de la herramienta de corte durante el mecanizado. Mediante la reflexión se destaca la importancia de los DIS como instrumentos de investigación científica en la manufactura, ya que estos permiten obtener muestras de viruta para estudiar las variables incidentes en el maquinado y a partir de esta evidencia, proponer alternativas para optimizar la fabricación de piezas y la integridad de las herramientas empleadas en el proceso.AbstractThe study of the variables and effects derived from the machining processes brings the knowledge needed to optimize the use of machining tools and procedures. This article is an opinion piece about the use of quick stop devices (QSD) as a scientific research instrument in machining projects to obtain chip roots, to study the interaction phenomena between cutting tool and work piece material that depends on temperature and the mechanical forces produced by the cutting tool during the cutting process. This article deals about how important the QSD are as a research instruments in manufacture because with this instruments it is possible to analyze the machining variables, based on the evidences bring by the chip roots obtained with the instrument. It is possible to propose optimization alternatives in the manufacture of machined parts and the integrity of cutting tools.

Tribological Behavior of Ni-Based Self-Lubricating Composites at Elevated Temperatures

2015 ◽  
pp. 72-106
Author(s):  
Jianliang Li ◽  
Dangsheng Xiong ◽  
Yongkun Qin ◽  
Rajnesh Tyagi
Keyword(s):  
High Temperature ◽  
Friction And Wear ◽  
Solid Lubricant ◽  
Elevated Temperatures ◽  
Wear Behavior ◽  
Composite Coatings ◽  
Solid Lubricants ◽  
Friction And Wear Behavior ◽  
Nickel Base ◽  
Self Lubricating Composites

This chapter illustrates the effect of the addition of solid lubricants on the high temperature friction and wear behavior of Ni-based composites. Ni-based composites containing solid lubricant particles both in nano and micrometer range have been fabricated through powder metallurgy route. In order to explore the possible synergetic action of a combination of low and high temperature solid lubricant, nano or micro powders of two or more solid lubricants were added in the composites. This chapter introduces the fabrication of the Ni-based self-lubricating composites containing graphite and/or MoS2, Ag and/or rare earth, Ag and/or hBN as solid lubricants and their friction and wear behavior at room and elevated temperatures. The chapter also includes information on some lubricating composite coatings such as electro-deposited nickel-base coating containing graphite, MoS2, or BN and graphene and their tribological characteristics.

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 High Temperature Friction and Wear Performance of PVD Coatings under Press Hardening Contact Conditions

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Sergej Mozgovoy ◽  
Jens Hardell ◽  
Braham Prakash
Keyword(s):  
Coefficient Of Friction ◽  
Elevated Temperatures ◽  
Adhesive Wear ◽  
Work Piece ◽  
Pvd Coatings ◽  
Tribological Behaviour ◽  
Press Hardening ◽  
Coated Tools ◽  
22Mnb5 Steel ◽  
Forming Tools

Press hardening is widely employed to produce automotive structural and safety components from advanced high-strength steels. This process depends on friction between the forming tools and the work piece. Wear of the forming tools affects the dimensional accuracy of produced components and reduces their service life. It is therefore desirable to reduce wear of forming tools for press hardening applications. One way to achieve this is by applying hard physical vapour deposited (PVD) coatings on the tool. In this work, the tribological behaviour of PVD coated tool-work piece material pairs has been studied at elevated temperatures in an experimental set-up simulating the tribological conditions in press hardening. Four different PVD coatings deposited on tool steel and uncoated tools as reference were studied during sliding against uncoated and Al-Si coated 22MnB5 steel. Results show that uncoated tools exhibited the lowest coefficient of friction when sliding against uncoated 22MnB5 steel. A CrWN coating initially showed low coefficient of friction but it increased with increasing sliding distance. A TiAlN coating and one of two AlCrN coatings showed similar frictional behaviour when sliding against uncoated 22MnB5 steel. During sliding against uncoated 22MnB5 steel, adhesive wear has been found to be the dominant wear mechanism. Adhesive wear was considerably reduced in the case of hard PVD coated tools in comparison to that of uncoated tools. During sliding against Al-Si coated 22MnB5 steel, no clear advantage in terms of friction behaviour of uncoated or PVD coated tools was observed. However, the transfer of Al-Si coating material from the work piece to the tools was significantly reduced for PVD coated tools. Frictional instabilities in all cases involving Al-Si coated work piece material further confirmed the occurrence of adhesive material transfer.

Mechanical Properties and Microstructure of Self-Lubricating Ceramic Cutting Tool Materials

2004 ◽  
Vol 471-472 ◽  
pp. 221-224 ◽  
Author(s):  
Jian Xin Deng ◽  
Tong Kun Cao ◽  
Jia Lin Sun
Keyword(s):  
Mechanical Properties ◽  
Cutting Tool ◽  
Solid Lubricants ◽  
Polished Surface ◽  
Ceramic Tool ◽  
Tool Materials ◽  
Ceramic Cutting Tool ◽  
Micro Cracks ◽  
The Difference ◽  
Cutting Tool Materials

Al2O3/TiC ceramic tool materials with the addition of solid lubricants such as BN and CaF2 were produced by hot pressing. Effect of the solid lubricants on the microstructure and mechanical properties has been studied. Results showed that AlN phase resulted from the reaction of Al2O3 with BN was formed in Al2O3/TiC/BN composite after sintering. Significant micro-cracks resulted from the residual stress owing to the difference in the thermal expansion coefficient were found on the polished surface, and caused large mechanical properties degradation. While Al2O3/TiC/CaF2 composite showed higher flexural strength, fracture toughness, and hardness compared with that of Al2O3/TiC/BN composite owing its porosity absent and finer microstructure.

Erosive wear performance of heat treated multi-component cast iron containing Cr, V, Mn and Ni eroded by alumina spheres at elevated temperatures

Wear ◽  
2017 ◽  
Vol 390-391 ◽  
pp. 135-145 ◽  
Author(s):  
Yao Zhang ◽  
Kazumichi Shimizu ◽  
Xinba Yaer ◽  
Kenta Kusumoto ◽  
V.G. Efremenko
Keyword(s):  
Cast Iron ◽  
Elevated Temperatures ◽  
Erosive Wear ◽  
Wear Performance ◽  
Heat Treated
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