Machinability of enamel under grinding process using diamond dental burrs

2019 ◽  
Vol 233 (11) ◽  
pp. 1151-1164
Author(s):  
Quan-Zhou Li ◽  
Cheng-Yong Wang ◽  
Li-Juan Zheng ◽  
Dan-Na Zhao ◽  
Chao-Feng Zeng
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Grit Size ◽  
Surface Grinding ◽  
Grinding Process ◽  
Diamond Grit ◽  
Dental Surgery ◽  
Normal Forces ◽  
Grinding Speed ◽  
Tangential Forces

Enamel grinding is a critical dental surgery process. However, tooth damage during the process remains a significant problem. Grinding forces, burr wear, and surface quality were characterised in relation to grinding speed, enamel orientation, grinding depth, and burr grit grain size. Results indicated that enamel rod orientation, grinding depth, and grinding speed critically affected enamel grinding. Occlusal surface grinding resulted in significantly higher normal forces, surface roughness, and marginally greater tangential forces than axial surface grinding. Damage to enamel machined surfaces indicated the significant impact of diamond grit size and rod orientation. Burr wear was primarily diamond grit peeling off and breakage. Surface roughness of axial and occlusal sections was largely influenced by grinding speed and diamond grit size. Improving the surface quality of machined enamel surfaces could be realised using fine burrs, reducing the grinding speed and grinding depth, and adjusting the feed direction vertical to the rod orientation. Enamel surface quality and roughness could be improved by reducing brittle failure and circular runout during the grinding process, respectively.

Study on Grinding Processing of Sapphire Wafer

2012 ◽  
Vol 565 ◽  
pp. 22-27 ◽  
Author(s):  
Yutaro Ebina ◽  
Wei Hang ◽  
Li Bo Zhou ◽  
Jun Shimizu ◽  
Teppei Onuki ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Dynamic Behavior ◽  
Surface Quality ◽  
Wheel Speed ◽  
Surface Grinding ◽  
Grinding Process ◽  
Sapphire Wafer ◽  
Diamond Grinding ◽  
Dominant Process ◽  
Diamond Grain

This paper reports our recent results on the diamond grinding process of single crystallized sapphire wafers. It was found that the diamond grains were severely dislodged at the wheel/ workpiece interface and the material was removed by a mixed process of both grinding and lapping. Grinding governed the wafer center while lapping dominated its fringe. By increasing the wheel speed, it was able to shift the dominant process from lapping to grinding, and achieve a better surface roughness. Nine diamond wheels varying in both concentration and bond material were tested in surface grinding of 6 inch sapphire wafer, to investigate the dynamic behavior of diamond grain in the grinding process and its resultant surface quality and productivity.

scholarly journals Effect of the bur grit size on the flexural strength of a glass-ceramic

Cerâmica ◽  
2016 ◽  
Vol 62 (362) ◽  
pp. 121-127 ◽  
Author(s):  
P. P. Kist ◽  
I. L. Aurélio ◽  
M. Amaral ◽  
L. G. May
Keyword(s):  
Surface Roughness ◽  
Flexural Strength ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
Internal Surface ◽  
Grit Size ◽  
Diamond Grit ◽  
Cad Cam ◽  
Negative Effect ◽  
Ceramic Blocks

Abstract The purpose of the present study was to determine the biaxial flexural strength (BFS) of a CAD/CAM leucite reinforced glass-ceramic ground by diamond burs of different grit sizes and the influence of surface roughness on the BFS. For this, 104 plates were obtained from CAD/CAM ceramic blocks and divided into 4 groups (n = 26), according to bur grit size: extra-fine, fine, medium and coarse. Roughness parameters (Ra, RyMax) were measured, and plates were kept dry for 7 days. The flexural test was carried out and BFS was calculated. Ra, RyMax and BFS data were subjected to analysis of variance and post-hoc test. Weibull analysis was used to compare characteristic strength and Weibull modulus. Regression analysis was performed for BFS vs. Ra and RyMax. When burs with coarse grit were used, higher surface roughness values were found, causing a negative effect on the ceramic BFS (117 MPa for extra-fine, and 83 MPa for coarse). Correlation (r) between surface roughness and BFS was 0.78 for RyMax and 0.73 for Ra. Increases in diamond grit size have a significant negative effect on the BFS of leucite-reinforced glass-ceramics, suggesting that grinding of sintered glass-ceramic should be performed using burs with the finest grit possible in order to minimize internal surface flaws and maximize flexural strength.

scholarly journals Experimental Study on The Effect of Cross Feed of Surface Grinding on the Vibration and the Surface Roughness of Hardened Tool Steel OCR12VM

2020 ◽  
Vol 11 (3) ◽  
pp. 313-322
Author(s):  
Chairul Anam ◽  
◽  
Khairul Muzaka ◽  
Dian Ridlo Pamuji
Keyword(s):  
Surface Roughness ◽  
Tool Steel ◽  
Dimensional Accuracy ◽  
Surface Grinding ◽  
Machining Process ◽  
Depth Of Cut ◽  
Grinding Process ◽  
Hardened Tool Steel ◽  
Stone Type ◽  
Grinding Stone

The grinding process is a machining process to obtain qualified surface roughness levels and high dimensional accuracy. There are two types of processes in the grinding process, namely the roughening and finishing processes. The vibration effect of the roughing process can damage and shorten the life of the tool/machine, while in the finishing process, the effect of vibration will reduce the dimensional accuracy, shape, and surface smoothness of the workpiece. This study aims to determine the effect of crossfeed on the amplitude of vibration and surface roughness of the workpiece on the surface grinding process. The materials used are hardened tool steel OCR12VM with a variety of grinding stone types A46QV and A80LV made of aluminum oxide. The Variables of process parameters are crossfeed (mm / step) and depth of cut (mm). The measurement of vibrations uses an accelerometer, which is processed by the math CAD program in the form of amplitude and frequency. For surface roughness measurements, it is used the MT-301 surface test with 5 sample points and a sample length of 0.8 mm. The results show that the greater the cross-feed value, the bigger the amplitude of the vibration level and the surface roughness of the workpiece. The magnitude of the amplitude of the vibration on the acceleration that occurs in the grinding stone type A46QV starts from 6,7369 -18.7525 g.rms, while the grinding stone type A80LV starts from 5.0904 g.rms to 18.2821 g.rms. The surface roughness achieved in both grit 46 and grit 80 is from N3 to N5.

scholarly journals Investigation of the Effect of Vibration Characteristics on the Grinding Performance of Aero-Engine Blade Tip

2021 ◽  
Author(s):  
Wei Li ◽  
Qidi Chen ◽  
Jian Wu ◽  
Mingjia Liu ◽  
Yinghui Ren ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Great Influence ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Aero Engine ◽  
Engine Blade ◽  
Blade Tip ◽  
The Difference

Abstract The machining quality of the blade tip has a great influence on the service performance and life of the aero-engine blade. The recent paper investigates the effect of vibration during the grinding process of the GH4169 nickel-based superalloy blade tip. Moreover, this paper proposes a theoretical model to link the unbalance of the grinding wheel, the vibration, and the surface topography characteristics of the blade. The results show that the blade vibration during grinding and the resulting non-linear change of the grinding depth could reduce the surface quality of the blade tip, and lead to differences in the surface quality of the blade tip in different areas, where the surface roughness in the entry area zone I is the largest, in the exit area zone III is the second largest, and the intermediate area zone III is the smallest. Grinding depth has a greater impact on the difference of the surface quality in the blade tip grinding process, especially when the grinding depth is greater than 4 μm, the difference of surface roughness increases significantly. On the other hand, the feed rate has little effect on the difference in surface quality. Adding damping block can reduce the surface roughness of the blade tip, however, it does not reduce the difference in surface quality.

Experimental Study on Micro-Grinding Process of Titanium Alloy Using Electro-Hydro-Dynamic Spray With Nanofluid and Compressed Air

2015 ◽  
Author(s):  
Pil-Ho Lee ◽  
Jung Soo Nam ◽  
Jung Sub Kim ◽  
Sang Won Lee
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Titanium Alloy ◽  
Surface Quality ◽  
Ground Surface ◽  
Experimental Results ◽  
Compressed Air ◽  
Grinding Process ◽  
Grinding Forces ◽  
Micro Scale

In this paper, the micro-scale grinding processes of titanium alloy (Ti-6Al-4V) using electro-hydro-dynamic (EHD) spray with nanofluid and compressed air are experimentally investigated. In the experiments, specific micro-grinding forces and surface roughness of the ground workpiece are quantitatively analyzed as a function of nanofluid’s concentration and size of nanoparticles. In addition, the ground surface quality is qualitatively investigated by comparing the optical microscopic images. The experimental results show the effectiveness of EHD spraying with nanofluid and compressed air for reducing the specific micro-grinding forces and enhancing ground surface quality.

Experimental Study on Cutting Performance in Micro-Grinding Hard Brittle Materials

2012 ◽  
Vol 565 ◽  
pp. 541-545
Author(s):  
Ya Dong Gong ◽  
Jun Cheng ◽  
Zhi Zheng Wu ◽  
Chao Wang ◽  
Jin Feng Zhang
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Surface Quality ◽  
Feed Rate ◽  
Brittle Materials ◽  
Soda Lime ◽  
Cutting Performance ◽  
Soda Lime Glass ◽  
Grinding Speed

The process of micro-grinding on hard brittle glass is shown in this paper, micro-grinding equipments are designed by tools of electroplated diamond, fz(feed rate), ap (grinding depth), vg(Grinding speed) in micro-grinding brittle materials and their effects to surface quality have been discussed. It has been demonstrated that low surface roughness could be achieved by high vg and low fz. The roughness of Soda-lime glass accomplished by fz:100μm/s, ap:30μm, vg:120000rpm in the experiment is about 78nm.

Experimental Study on Surface Finishing Performances in Quick-Point Grinding

2007 ◽  
Vol 24-25 ◽  
pp. 97-102 ◽  
Author(s):  
Shi Chao Xiu ◽  
Chang He Li ◽  
Guang Qi Cai
Keyword(s):  
Surface Roughness ◽  
Feeding Rate ◽  
Point Contact ◽  
Surface Finishing ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Cylindrical Grinding ◽  
Axial Feeding ◽  
Grinding Speed

There are lower grinding force and temperature in quick-point grinding process because of the higher grinding speed and the less depth of cut, especially the point contact between the grinding wheel and the workpiece due to the point grinding angles. Thus it can achieve better surface finishing process in grinding cylindrical surface. Since the point grinding model is different from the conventional cylindrical grinding in theory, the surface roughness is in relation to the point-grinding angles greatly besides the grain granularity, depth of cut, grinding speed and axial feeding rate like the conventional cylindrical grinding process. Based on the theoretical studies on the surface roughness in the process, the surface finishing experiments and measures at the various grinding parameters were performed. The experimental results show that the process parameters, such as point-grinding angles, depth of cut, grinding speed and axial feeding rate, must be controlled reasonably for the higher surface finishing demand in quick-point grinding process.

The study on surface grinding process of TI–6AL–4V alloy with resinoid cBN grinding wheel

2020 ◽  
Vol 34 (22n24) ◽  
pp. 2040135
Author(s):  
Phi-Trong Hung ◽  
Hoang-Tien Dung ◽  
Nguyen-Kien Trung ◽  
Truong-Hoanh Son
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Chemical Reactivity ◽  
Surface Grinding ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Wet Grinding ◽  
Ti Alloys ◽  
Cbn Grinding Wheel

The grinding process of Titanium (Ti) alloys is extremely difficult as the cutting temperature is much higher than other machining processes due to the low thermal conductivity, high chemical reactivity, and rapid work hardening during machining of Ti alloys. This research investigates the effect of technology parameters on the surface roughness in the surface grinding of Ti–6Al–4V (Ti64) alloy with resinoid cBN grinding wheel. The experimental results show that the surface roughness is significantly affected by the feed rate, depth of cut (DOC) and cooling condition. Increasing feed rate or DOC all provides the higher surface roughness. The surface roughness obtained in the wet grinding is higher than those of the dry cutting. The scanning electron microscopy (SEM) images of Ti64 surfaces show that the machining surface with fewer defects can be produced with wet grinding process.

Surface Quality Effects Investigation of Micro-Grinding Soda-Lime Glass

2012 ◽  
Vol 251 ◽  
pp. 397-401
Author(s):  
Jun Cheng ◽  
Ya Dong Gong ◽  
Zhi Zheng Wu ◽  
Xu Qiang Yan ◽  
Wei Sheng Zheng
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Feed Rate ◽  
Brittle Materials ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Effective Factors ◽  
Grinding Speed ◽  
Micro Machine

This paper presents a micro-grinding experiment on soda-lime glass to study the surface quality effective factors during micro grinding on hard brittle materials. The process of micro-grinding on soda-lime glass is showed in this paper and micro-grinding equipments are designed, fz(feed rate), ap (grinding depth), vg(Grinding speed) in micro-grinding brittle materials and their effects to surface quality have been discussed by experiments which were carried out on a desktop micro machine developed by NEU. Results proved that fz is the most important factor to the surface quality, and low surface roughness could be achieved by high vg and low fz in micro-grinding soda-lime glass.

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