scholarly journals Study of the machining quality of CMC ceramic composite during high-speed grinding

2021 ◽  
Vol 1901 (1) ◽  
pp. 012095
Author(s):  
D S Rechenko ◽  
R U Kamenov
Keyword(s):  
High Speed ◽  
Ceramic Composite ◽  
Machining Quality ◽  
High Speed Grinding

Machining quality of high speed helical milling of carbon fiber reinforced plastics

2021 ◽  
pp. 095440622199673
Author(s):  
Adel Abidi ◽  
Sahbi Ben Salem ◽  
Mohamed Athmane Yallese
Keyword(s):  
Surface Roughness ◽  
Carbon Fiber ◽  
High Speed ◽  
Hole Diameter ◽  
Feed Speed ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Machining Quality ◽  
Fiber Reinforced Plastics

Among advanced cutting methods, High Speed Milling (HSM) is often recommended to improve the productivity and to reduce the costs of machining parts. As every cutting process, HSM is characterized by some defects like surface roughness and delamination are the main defects generated in composite materials. The aim of this experimental work is the studying of the machining quality of woven Carbon fiber reinforced plastics (CFRP) using the HSM technology. Experiments were done using different machining parameters combinations to make opened holes in CFRP laminates. This study investigated the effect of cutting speed, orbital feed speed, hole diameter on the delamination defect and surface roughness responses generated in the drilled holes. The design of experimental tests was generated using the approach of Central Composite Design (CCD). The characterization of these responses was treated with the Analysis of variance (ANOVA) and Response surface methodology (RSM). Results showed that the surface roughness is highly affected by the orbital feed speed (F) with contribution of 22.45%. The delamination factor at entry and exit of holes is strongly influenced by the hole diameter D (25.97% and 57.43%) respectively. The developed model equations gave a good correlation between the empirical and predicted results. The optimization of the milling parameters was treated using desirability function to minimize the surface roughness (Ra) and the delamination factor simultaneously.

scholarly journals Mechanism of Chip Formation Process at Grinding

2019 ◽  
Vol 297 ◽  
pp. 09002
Author(s):  
Vyacheslav Shumyacher ◽  
Sergey Kryukov ◽  
Olga Kulik ◽  
Xavier Kennedy
Keyword(s):  
Formation Process ◽  
Chip Formation ◽  
High Speed ◽  
Cutting Speed ◽  
Dimensional Accuracy ◽  
Processing Parameters ◽  
Abrasive Grain ◽  
Wave Heating ◽  
High Speed Grinding

The mechanism of chip formation process at grinding is described, which involves a high-speed interaction of abrasive grain and metal, which leads to a concentration of thermal energy in front of the dispersing element (grain), causing a locally concentrated shift in the metal microvolume. In “abrasive grain -metal” contact a dissipative structure is formed which existence is supported by exchange of energy and substance with environment. Due to shock compression of the metal microvolume with abrasive grain, shock-wave heating is realized, initiating emission of electrons ionizing the lubricating cooling fluid in the zone of formation of side micro-scratches left by abrasive. The results obtained in the course of the research can be used to explain the mechanisms of chip formation, as well as the course of the physical and mechanical processes occurring on the surface layers of the grinded workpieces. By controlling chip formation processes at high-speed grinding, by optimally selecting the appropriate ratios between cutting speed and other processing parameters, a reduction in process thermal density can be achieved, which, with the highest productivity, will allow to obtain the required quality of the surface layer of the workpieces and a given dimensional accuracy.

Influences of Ultrasonic Assistance in High Speed Lapping of Nano ZTA Engineering Ceramic on the Surface Machining Quality

2007 ◽  
Vol 359-360 ◽  
pp. 355-359 ◽  
Author(s):  
Feng Jiao ◽  
Bo Zhao ◽  
Chuan Shao Liu ◽  
Xun Sheng Zhu
Keyword(s):  
High Speed ◽  
Chip Thickness ◽  
Surface Profile ◽  
Abrasive Material ◽  
Regular Surface ◽  
Surface Machining ◽  
Machining Quality ◽  
Engineering Ceramic ◽  
Precision Finishing

Ultrasonic aided high speed lapping with solid abrasive material was put forward aimed at the precision finishing of nano ZTA engineering ceramic. Through theoretical analysis and contrast lapping experiments, the influences of ultrasonic assistance on the surface machining quality were clarified. Research results show that the maximum undeformed chip thickness in ultrasonic aided lapping is smaller than that in conventional lapping under the same conditions; ultrasonic assistance is beneficial to enlarging the range of ductile lapping regime and improving the surface quality of nano ZTA ceramic; with the application of ultrasonic vibration, smaller surface roughness and more regular surface profile can be obtained.

scholarly journals Experimental study of single cubic boron nitride grains in the ultrasound-assisted high-speed grinding

2017 ◽  
Vol 9 (2) ◽  
pp. 168781401769354 ◽  
Author(s):  
Dao-hui Xiang ◽  
Zhong-yun Liu ◽  
Zhi-kun Zhou ◽  
Yun-long Yao
Keyword(s):  
Experimental Study ◽  
Boron Nitride ◽  
Surface Quality ◽  
High Speed ◽  
Cubic Boron Nitride ◽  
Grinding Force ◽  
Abrasive Particles ◽  
Ultrasonic Assisted ◽  
High Speed Grinding

The kinematic characteristics, grinding force, surface quality of workpiece surface, and wear of abrasive particles were studied by theoretical analysis and experimental study on the single cubic boron nitride abrasive particles under ultrasonic-assisted high-speed grinding. Under the condition of the same grinding parameters, the motion characteristics and the grinding forces of the two machining modes of general grinding and ultrasonic-assisted grinding are compared and analyzed. Research shows that the ultrasonic vibration is applied in the common external circular grinding on grinding particle movement characteristics changed obviously, grinding particle trajectory of variable length, cutting groove width wider, thereby improving the grinding efficiency and the grinding removal rate; ultrasonic assisted under high speed grinding, the grinding force is higher than that of common grinding force is small, efficiency of grinding under ultrasonic processing mode is much higher than ordinary grinding, the surface quality of the workpiece has improved markedly.

Research on Heat Transfer and Calculation Method of Workpiece Surface Temperature in High Speed Grinding

2011 ◽  
Vol 325 ◽  
pp. 28-34
Author(s):  
Bei Zhi Li ◽  
Da Hu Zhu ◽  
Zhen Xin Zhou ◽  
Jing Zhu Pang ◽  
Jian Guo Yang
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
High Speed ◽  
Removal Rate ◽  
Convective Heat Transfer Coefficient ◽  
Calculation Model ◽  
Grinding Wheel ◽  
Workpiece Surface ◽  
High Speed Grinding

The surface quality of workpiece depends largely on workpiece surface temperature in grinding. The key parameters on workpiece surface temperature calculation model have been researched and the calculation model constructed in this paper, including the convective heat transfer coefficient (CHTC) (hf), heat flux (qch) and the grain contact half-width (r0) which are assumed to be constant in workpiece surface temperature model given by Rowe. And the improved Rowe model has been proposed (Rowe/Li model) which not only involves the grinding process parameters such as the speed of wheel and workpiece, but also the geometric parameters of workpiece, grinding wheel and abrasive. The experimental results of the surface temperature in high-speed grinding are very close to the results by Rowe / Li model. Relative to the Rowe model, the obtained surface temperature by Rowe / Li model has decreased by about 35-40%. Under the conditions of the same material removal rate, high-speed grinding, namely, increasing wheel speed can effectively reduce the surface temperature and improve the grinding quality.

scholarly journals Flat grinding effectiveness increase due to rational work cycle use

2020 ◽  
Vol 2020 (9) ◽  
pp. 7-11
Author(s):  
Yuriy Zubarev ◽  
Alexsandr Priyomyshev
Keyword(s):  
Hard Alloy ◽  
Labor Productivity ◽  
High Speed ◽  
Work Cycle ◽  
High Speed Grinding ◽  
Grinding Machines ◽  
Production Areas

A possibility for machinery billet machining effectiveness increase at the expense of the use of high-speed grinding machines operated in an automated cycle of machining mode changes is considered. It allows performing operations of roughing and then finishing ensuring the required accuracy and quality of surfaces worked. The application of high-speed force grinding allows rejecting rough and finish preliminary milling and, in such a way, decreasing the number of machine equipment, hard-alloy cutters, production areas and increasing labor productivity.

Study on Balance Precision of Ultra-High Speed CBN Grinding Wheel System

2008 ◽  
Vol 375-376 ◽  
pp. 614-618 ◽  
Author(s):  
Shi Chao Xiu ◽  
Jian Liu ◽  
Chang He Li ◽  
Guang Qi Cai
Keyword(s):  
High Speed ◽  
Dynamic Performance ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Rigid Rotor ◽  
Machining Quality ◽  
Ultra High Speed ◽  
High Speed Grinding ◽  
Cbn Grinding Wheel ◽  
Grinding System

The balance precision of grinding wheel is a key technical parameter in ultra-high speed grinding process. The actual standard for the balance precision of rigid rotor is not fit for the thin ultra-high speed grinding system well. The unbalance factors affected on the ultra-high speed grinding wheel and its system were analyzed, and its effects on the machining quality in the process were also discussed. The theory and select principle of the balance precision for ultra-high speed grinding wheel system were studied. The test of dynamic performance was performed for the thin ultra-high speed CBN grinding wheel system whose structure was optimized. The groundwork to establish the standard of balance precision for thin ultra-high speed grinding system was offered.

Study on Acoustic Emission During High-Speed Grinding and Ultraprecision Grinding of Advanced Ceramics

1999 ◽  
Author(s):  
S. Gowri ◽  
Bryan K. A. Ngoi ◽  
K. Ramesh
Keyword(s):  
Residual Stress ◽  
Material Removal ◽  
High Speed ◽  
Acoustic Emissions ◽  
Ceramic Surfaces ◽  
High Speed Grinding ◽  
Grinding Conditions ◽  
Machining Productivity ◽  
Brittle Mode

Abstract The process of grinding produces characteristic acoustic emissions (AE) and the signals of AE could be used as ‘condition monitoring’ tool to understand the phenomenon involved in material removal. It has been observed that high-speed grinding of the ceramics improved machining productivity without deteriorating the surface quality of the ceramics, which is not common in the case of metals. Residual stress analysis on the machined ceramics indicated that built-in residual stress might have reduced the crack-formation. Critical grinding conditions limiting the formation of cracks on the ceramics were identified. The trend in AErms signals could be correlated to the grinding force and the grinding conditions. In case of ultraprecision machining, the ductile regime grinding of the ceramics was found out in terms of feed and depth of grinding with grinding velocity. Analysis with the SEM of machined ceramic surfaces and the AErms could reveal the occurrence of ductile regime grinding and also the transition of ductile to conventional brittle mode of material removal during grinding.

Balancing of Tool/Toolholder Assembly for High-Speed Machining

2004 ◽  
Vol 471-472 ◽  
pp. 542-546
Author(s):  
Song Zhang ◽  
Xing Ai ◽  
Wei Xiao Tang ◽  
J.G. Liu
Keyword(s):  
Centrifugal Force ◽  
Rotational Speed ◽  
High Speed ◽  
Manufacturing Industry ◽  
High Speed Machining ◽  
High Rotational Speed ◽  
Good Balance ◽  
Machining Quality ◽  
System Maintenance

High-speed machining has become mainstream in machining manufacturing industry. In industries such as moldmaking and aerospace, it has become the norm rather the exception. The centrifugal force increases as the square of the speed. At rotational spindle speeds of 6,000 r/min and higher however, centrifugal force from unbalance becomes a damaging factor and it reduces the life of the spindle and the tool, as well as diminishes the quality of the finished product. Under high rotational speed, good balance becomes issue. High-speed machining experimental results shown that a well-balanced tool/toolholder assembly could obviously improve machining quality, extend tool life and shorten downtime for spindle system maintenance etc.

Experimental Investigation and Improvement of Dynamic Performance of High-Speed Grinding Machine

2010 ◽  
Vol 156-157 ◽  
pp. 1609-1612 ◽  
Author(s):  
Xiao Long Shen ◽  
Cheng Gao Ren ◽  
Zhi Mou Pi ◽  
Dai Li Zhu
Keyword(s):  
High Speed ◽  
Dynamic Performance ◽  
Power Spectra ◽  
Weak Links ◽  
Machining Accuracy ◽  
Variable Speed ◽  
High Speed Grinding ◽  
Improvement Measures ◽  
Grinding Machine

Design of the dynamic performance of a machine tool is an effective approach to improve the machining accuracy. In this paper, the dynamic performance of high-speed cylindrical grinder has been studied systematically to improve the surface quality of high-speed grinding. According to the mode shape graphs and the power spectra, the vibration weak links and the main vibration sources of the prototype were found, and then the improvement measures were presented by designing the dynamic performance tests. The fact that the chatter of high-speed grinding can be suppressed to a certain extent with variable speed grindings was verified in variable speed grinding experiments at high speed.

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