Energy Partition in Conventional Surface Grinding

1999 ◽  
Vol 121 (3) ◽  
pp. 393-398 ◽  
Author(s):  
T. Kato ◽  
H. Fujii

In order to estimate the energy partition to the workpiece in surface grinding, the temperatures at various depths from the ground surface of the workpiece were measured using the PVD (physical vapor deposition) film method developed by the authors. In this method a thin film deposited on the workpiece is used as a thermal sensor. The energy partition for various grinding wheels was estimated with the maximum temperature rise at the surface obtained by extrapolating the temperatures measured at various depths. It was found that the partition changes significantly from 0.3 to 0.8, depending on the combination of the workpiece material and the wheel material in conventional dry surface grinding.

1998 ◽  
Vol 122 (2) ◽  
pp. 297-303 ◽  
Author(s):  
T. Kato ◽  
Hiroshi Fujii

Temperature at various depths from the ground surface in workpiece is measured accurately by using the newly developed PVD film method, in which a thin film deposited on the workpiece is used as a thermal sensor. The influence of workpiece speed, depth of cut and wheel speed on the temperature of the workpiece was investigated under conventional surface grinding with no grinding fluids. The measured results were compared with Takazawa’s approximation based on Jaeger’s heat conduction solution to the moving heat source problem. The maximum temperature rise at the surface and the temperature gradient close to the surface were obtained and correlated with the residual stress induced at the surface. [S1087-1357(00)70302-9]


Author(s):  
Bin Shen ◽  
Guoxian Xiao ◽  
Changsheng Guo ◽  
Stephen Malkin ◽  
Albert J. Shih

A new thermocouple fixation method for grinding temperature measurement is presented. Unlike the conventional method using a welded thermocouple, this new method uses epoxy for affixing the embedded thermocouple within a blind hole in the workpiece subsurface. During grinding, the thermocouple junction is exposed and bonded to provide direct contact with the ground surface by the smearing of the workpiece material. Experiments were conducted to evaluate this simplified thermocouple fixation method including the effect of thermocouple junction size. Heat transfer models were applied to calculate the energy partition for grinding under dry, wet, and minimum quantity lubrication (MQL) conditions. For shallow-cut grinding of cast iron using a vitreous bond aluminum oxide wheel, the energy partition using a small wheel depth of cut of 10 μm was estimated as 84% for dry grinding, 84% for MQL grinding, but only 24% for wet grinding. Such a small energy partition with wet grinding can be attributed to cooling by the fluid at the grinding zone. Increasing the wheel depth of cut to 25 μm for wet grinding resulted in a much bigger energy partition of 92%, which can be attributed to fluid film boiling and loss of cooling at the grinding zone.


2016 ◽  
Vol 1136 ◽  
pp. 71-77
Author(s):  
Bahman Azarhoushang ◽  
Rolf Rinderknecht ◽  
Alireza Vesali ◽  
Juergen Struss

The loading of the grinding wheel and adhesion of the workpiece material to the cutting edges of the grinding tool are among the main reasons which limit the process efficiency when grinding ductile materials. The micro topography of the grinding tool changes drastically as a result of loading. Higher grinding forces and temperatures, poorer surface quality and process accuracy are the consequences of the adhesion of the workpiece material to the grinding tool surface. A novel and promising technique to reduce the possibility of loading and adhesion in the grinding process is the infiltrating of the grinding tool. This study describes the results of infiltration of vitrified bonded conventional grinding wheels with graphite in the surface grinding process. The effects of infiltration have been studied for the first time on various grinding wheels with different grain materials, grit sizes, porosity and hardness. Two different types of steel which are very popular in the automobile industry, 100Cr6 and 16MnCr5, were chosen as the workpiece material by the surface grinding experiments. The selected cutting parameters cover a wide range of the practical surface grinding processes which are utilized generally in the industry. It has been experimentally shown that the type of infiltration plays an important role in reducing the loading of the wheel. Better surface quality and longer dressing intervals are the main results of the infiltration of the grinding tools.


Author(s):  
V. C. Kannan ◽  
S. M. Merchant ◽  
R. B. Irwin ◽  
A. K. Nanda ◽  
M. Sundahl ◽  
...  

Metal silicides such as WSi2, MoSi2, TiSi2, TaSi2 and CoSi2 have received wide attention in recent years for semiconductor applications in integrated circuits. In this study, we describe the microstructures of WSix films deposited on SiO2 (oxide) and polysilicon (poly) surfaces on Si wafers afterdeposition and rapid thermal anneal (RTA) at several temperatures. The stoichiometry of WSix films was confirmed by Rutherford Backscattering Spectroscopy (RBS). A correlation between the observed microstructure and measured sheet resistance of the films was also obtained.WSix films were deposited by physical vapor deposition (PVD) using magnetron sputteringin a Varian 3180. A high purity tungsten silicide target with a Si:W ratio of 2.85 was used. Films deposited on oxide or poly substrates gave rise to a Si:W ratio of 2.65 as observed by RBS. To simulatethe thermal treatments of subsequent processing procedures, wafers with tungsten silicide films were subjected to RTA (AG Associates Heatpulse 4108) in a N2 ambient for 60 seconds at temperatures ranging from 700° to 1000°C.


Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 851
Author(s):  
Svetlana I. Dorovskikh ◽  
Evgeniia S. Vikulova ◽  
Elena V. Chepeleva ◽  
Maria B. Vasilieva ◽  
Dmitriy A. Nasimov ◽  
...  

This work is aimed at developing the modification of the surface of medical implants with film materials based on noble metals in order to improve their biological characteristics. Gas-phase transportation methods were proposed to obtain such materials. To determine the effect of the material of the bottom layer of heterometallic structures, Ir, Pt, and PtIr coatings with a thickness of 1.4–1.5 μm were deposited by metal–organic chemical vapor deposition (MOCVD) on Ti6Al4V alloy discs. Two types of antibacterial components, namely, gold nanoparticles (AuNPs) and discontinuous Ag coatings, were deposited on the surface of these coatings. AuNPs (11–14 nm) were deposited by a pulsed MOCVD method, while Ag films (35–40 nm in thickness) were obtained by physical vapor deposition (PVD). The cytotoxic (24 h and 48 h, toward peripheral blood mononuclear cells (PBMCs)) and antibacterial (24 h) properties of monophase (Ag, Ir, Pt, and PtIr) and heterophase (Ag/Pt, Ag/Ir, Ag/PtIr, Au/Pt, Au/Ir, and Au/PtIr) film materials deposited on Ti-alloy samples were studied in vitro and compared with those of uncoated Ti-alloy samples. Studies of the cytokine production by PBMCs in response to incubation of the samples for 24 and 48 h and histological studies at 1 and 3 months after subcutaneous implantation in rats were also performed. Despite the comparable thickness of the fibrous capsule after 3 months, a faster completion of the active phase of encapsulation was observed for the coated implants compared to the Ti alloy analogs. For the Ag-containing samples, growth inhibition of S. epidermidis, S. aureus, Str. pyogenes, P. aeruginosa, and Ent. faecium was observed.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 215
Author(s):  
Andreia A. Ferreira ◽  
Francisco J. G. Silva ◽  
Arnaldo G. Pinto ◽  
Vitor F. C. Sousa

PVD (physical vapor deposition) and CVD (chemical vapor deposition) have gained greater significance in the last two decades with the mandatory shift from electrodeposition processes to clean deposition processes due to environmental, public safety, and health concerns. Due to the frequent use of coatings in several industrial sectors, the importance of studying the chromium coating processes through PVD–sputtering can be realized, investing in a real alternative to electroplated hexavalent chromium, usually denominated by chromium 6, regularly applied in electrodeposition processes of optical products in the automotive industry. At an early stage, experimental tests were carried out to understand which parameters are most suitable for obtaining chromium coatings with optical properties. To study the coating in a broad way, thickness and roughness analysis of the coatings obtained using SEM and AFM, adhesion analyzes with the scratch-test and transmittance by spectrophotometry were carried out. It was possible to determine that the roughness and transmittance decreased with the increase in the number of layers, the thickness of the coating increased linearly, and the adhesion and resistance to climatic tests remained positive throughout the study. Thus, this study allows for the understanding that thin multilayered Cr coatings can be applied successfully to polymeric substrates regarding optical applications in the automotive industry.


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