From abrasive size to subsurface damage in grinding

Author(s):  
John Lambropoulos
2019 ◽  
Vol 963 ◽  
pp. 530-533
Author(s):  
Kevin Moeggenborg ◽  
Ian Manning ◽  
Jon Searson ◽  
Gil Yong Chung

The impact of surface stress due to polish and grind processes on wafer bow was studied as a function of abrasive size. Results indicate that sub-surface damage from these processes can introduce significant surface stress. For polishing processes, this stress is proportional to mean abrasive size. The study also investigates stress as a function of depth below the wafer surface and finds that most stress is concentrated near the wafer surface.


Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5824
Author(s):  
Weronika Czepułkowska-Pawlak ◽  
Emilia Wołowiec-Korecka ◽  
Leszek Klimek

Abrasive blasting is a process widely used in dentistry. One of the uses is the development of metal surfaces for connections with ceramics in fixed prosthetic restorations. The purpose of this paper was to check how the rough surface profile (width, height, and depth on unevenness) impacts the surface’s condition, like its wettability and percentage of stuck abrasives. The Ni-Cr alloy surface was abrasive blasted by silicon carbide with the various pressure parameters (0.2, 0.4, and 0.6 MPa) and abrasive particle sizes (50, 110, and 250 µm). Cleaned surfaces were examined for roughness, wettability, and percentage of stuck abrasive particles on the surface. The surface after abrasive blasting using 110 µm of abrasive size and 0.4 MPa pressure has the best wettability results. The width of unevenness may cause it. When the unevenness has too small or too large width and depth, the fluids may not cover the entire cavities because of locking the air. The surface condition of dental alloys directly affects metal–ceramic connection strength. The knowledge about the impact of the abrasive blasting parameters on the bond strength will allow one to create durable dental restorations.


Author(s):  
Raj Kumar Singh ◽  
Amit Telang ◽  
Satyabrata Das

Abstract The effects of friction heat and friction coefficient on the abrasive wear response of Al-7.5Si–SiCp composite against low-cost hypereutectic (Al-17.5Si) alloy were investigated as functions of the abrasive size and applied load in both as-cast and after heat-treatment conditions. Experiments were performed on pin-on-disc apparatus at 38 –80 μm abrasive size, 5 – 20 N applied load, 100 –400 m abrading (sliding) distances and 1 m s–1 constant sliding speed. The frictional heating of as-cast and heat-treated composite was superior compared to the matrix alloy and hypereutectic alloy, whereas the trend reversed for the friction coefficient. The frictional heating and friction coefficient of the materials increased with the abrasive size and applied load in both as-cast and after heat-treatment. The worn surface and wear debris particles were examined by using field emission scanning electron microscopy to understand the wear mechanism.


2006 ◽  
Vol 304-305 ◽  
pp. 276-280 ◽  
Author(s):  
Y.H. Ren ◽  
Zhi Xiong Zhou ◽  
Zhao Hui Deng

Surface microgrinding of the nanostructured WC/12Co coatings have been undertaken with diamond wheels under various conditions. Nondestructive and destructive approaches were utilized to assess damage in ground nanostructured coatings. Different surface and subsurface configurations were observed by scanning electron microscopy. This paper investigates the effects of microgrinding conditions on damage formation in the surface and subsurface layers of the ground nanostructured WC/12Co coatings. And the material-removal mechanism has been discussed.


2007 ◽  
Vol 353-358 ◽  
pp. 864-867 ◽  
Author(s):  
Hai Yang Yu ◽  
Zhen Sun ◽  
Hua Zhao ◽  
Min Hao Zhu

In the subsurface damage observations on the wear behavior of brittle dental porcelains, it still remains unsolved that how to distinguish the cracks that develops accidentally during the preparing sample process from those actually produced in the tests. In the sliding friction tests, the bonded-interface technique (BIT) was successfully used for subsurface damage evaluations. The profile of wear scar was easily observed on the cemented section of the blocks without inducing any cracks. The stresses on the surface and internal of dental porcelains were calculated with the contact element method (CEM) by ABAQUS software. The model of rectangular dental porcelain and Si3N4 ball were developed based on sliding friction tests. The Si3N4 ball modeled in this study was of the diameter of 4mm and 12 mm. The size of Vita VMK 95 porcelain blocks was 5 mm wide, 2 mm thick and 15 mm long. The glue layer thickness values are 10 .m, 20 .m and 30 .m. The loading of the Si3N4 ball was modeled as a constant distributed vertical load applied across the bonding line of the porcelain. Stresses and displacements of all nodes of the model, especially at the bonding interface, were analyzed and compared. The results of the study indicated that stress values correlated strongly to the applied loads. Stress distribution was symmetric about the bonded-interface plane. The maximum occurred in surface layer and the minimum on the bottom line in the porcelain blocks. Along the interface, stresses decreased with the distance from the surface of porcelain. On the other hand, high stresses focus on the surface part and go sharply down in the internal region along the depth direction. Among the parameters of sliding test on the stresses, the load effect is prominent. The BIT model experiences a different, non-axisymmetric stress field than that of real work-piece. So the BIT should not be considered as a reliable source of quantitative analysis but as a qualitative method for observing the form of the damage modes with more visible information than the conventional tools.


2016 ◽  
Vol 114 ◽  
pp. 148-157 ◽  
Author(s):  
Katelyn Freeseman ◽  
Lev Khazanovich ◽  
Kyle Hoegh ◽  
Alireza Nojavan ◽  
Arturo E. Schultz ◽  
...  

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