The Experiment Research of Precision Grinding of Li-Ti Ferrite with Graphite Grinding Wheel

2010 ◽  
Vol 431-432 ◽  
pp. 322-325
Author(s):  
Bei Zhang ◽  
Hong Hua Su ◽  
Hong Jun Xu ◽  
Yu Can Fu

Li-Ti ferrite used in aviation occasions needs good surface quality. In conventional grinding it is difficult to meet the surface demand. Accordingly, this paper proposed a new grinding process to change the situation. The process employed graphite grinding wheel which is always used in ultra-precision grinding of steel piece. The process can obtain good surface quality and ensure certain material removal rate. The ground surface appearance is nearly mirror-like. The lowest surface roughness of Ra value of the ground surface is 0.05μm in the experiment. The ground surface morphology is made up of spread glazed area and dispersed minute pits. The ductile regime dominates the material removal mechanism and no surface damage is induced in the process. In consideration of the results in the experiment it can be seen that grinding with graphite grinding wheel is a good finishing procedure in ferrite machining because of its obtained high surface quality.

2009 ◽  
Vol 69-70 ◽  
pp. 113-117
Author(s):  
Qian Fa Deng ◽  
Dong Hui Wen ◽  
Feng Chen ◽  
Li Tao ◽  
Ju Long Yuan

To obtain high surface quality and high finishing efficiency in machining SUS440 stainless steel, a novel machining technology employing a semi-fixed abrasive plate (SFAP) is adopted. The SFAP is developed for preventing lapped surface from damage caused by larger particles (from grain size dispersion or from outside of processing area, larger particles could bring uneven load distribution on processing region). The effects of different parameters on the surface quality and the material removal rate (MRR) of SUS440 stainless steel which is lapped by SFAP are investigated in this paper. The control parameters of the lapping process include the lapping time, the load, the rotating speed of the lapping plate, and etc. SFAP of 800# SiC abrasive used, Experimental results indicate that SFAP can avoid the large scratch effectively and the surface roughness (Ra) of the workpiece could be improved from 250 nm to 50 nm in 12 Min. A nearly mirror-like surface can be obtained.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Adel T. Abbas ◽  
Karim Hamza ◽  
Mohamed F. Aly ◽  
Essam A. Al-Bahkali

This paper presents a multiobjective optimization study of cutting parameters in turning operation for a heat-treated alloy steel material (J-Steel) with Vickers hardness in the range of HV 365–395 using uncoated, unlubricated Tungsten-Carbide tools. The primary aim is to identify proper settings of the cutting parameters (cutting speed, feed rate, and depth of cut) that lead to reasonable compromises between good surface quality and high material removal rate. Thorough exploration of the range of cutting parameters was conducted via a five-level full-factorial experimental matrix of samples and the Pareto trade-off frontier is identified. The trade-off among the objectives was observed to have a “knee” shape, in which certain settings for the cutting parameters can achieve both good surface quality and high material removal rate within certain limits. However, improving one of the objectives beyond these limits can only happen at the expense of a large compromise in the other objective. An alternative approach for identifying the trade-off frontier was also tested via multiobjective implementation of the Efficient Global Optimization (m-EGO) algorithm. The m-EGO algorithm was successful in identifying two points within the good range of the trade-off frontier with 36% fewer experimental samples.


2014 ◽  
Vol 1027 ◽  
pp. 68-71 ◽  
Author(s):  
Jian Bin Wang ◽  
Yong Wei Zhu ◽  
Jun Xu ◽  
Zhan Kui Wang ◽  
Ji Hua Miao

The processing technology of sapphire with a high material removal rate a good surface quality is critical for its applications. The experiment of sapphire lapping and polishing was carried out by using three different fixed abrasive pad (FAP). Their material removal rate (MRR) and surface roughness (Ra) were measured and analyzed. Results indicate that a MRR of 5.6μm/min reaches in rough lapping and a MRR of 0.4μm/min in fine lapping. The average surface roughness Ra of rough lapping and fine lapping is 142nm and 1.2nm respectively. The processing efficiency of sapphire wafer is effectively improved and a good surface quality is obtained when FAP adopted.


2010 ◽  
Vol 458 ◽  
pp. 307-312 ◽  
Author(s):  
Yi Quan Yu ◽  
Jian She Zhao ◽  
Bing Hui Li ◽  
Jia Wen Xu

For the difficulties of machining small hole on difficult-to-cut materials, a study of hole-making technology by pulsed electrolyte jet machining is carried out. Main effects of DC power and pulse power on the hole conicity, surface quality and drilling efficiency are studied in this paper. The experiment results show that: hole with high surface quality can be available and the hole conicity is effectively reduced by using pulsed electrolyte jet machining; DC is suitable for improving efficiency when the ECM voltage is less than 300V, while pulse power supply shall be adopted to achieve good surface quality and high drilling efficiency when the ECM voltage is more than 300V.


2013 ◽  
Vol 457-458 ◽  
pp. 172-176
Author(s):  
Zong Fu Guo ◽  
Xiao Min Sheng ◽  
Gui Zhi Xie ◽  
De Zhen Yin ◽  
Wen Xin Li

This paper via investigate the process of 9SiCr alloy steel in high efficiency deep grinding to find the rule between grinding wheel speed vs depth of cut ap and speed of table vw with the grinding force and the surface quality. Intend to develop a suitable method of the grinding process of 9SiCr alloy steel in high efficiency deep grinding, to obtain high removal rate and good surface quality.


Author(s):  
Xinxiao Li ◽  
Patrick Chernjavsky ◽  
Katerina Angjeli ◽  
Sola Hoffman ◽  
Sara Frunzi ◽  
...  

Abstract Rotational atherectomy (RA) utilizes a high-speed, metal-bonded diamond-abrasive grinding wheel to remove the calcified atherosclerotic plaque inside arteries, restore blood flow, and treat cardiovascular diseases. RA operational guidelines have been clinically investigated to improve clinical outcomes and reduce complication rates, but are still in lack of consensus. Particularly, the effect of the grinding wheel rotational speed on plaque material removal rate (MRR) is unclear. This study experimentally investigates the RA MRR over a range of wheel rotational speeds based on a vascular simulator with a calcified plaque surrogate. The MRR, presented as the luminal area gain, with the increase of the number of grinding passes, was measured at the rotational speed of 120,000, 150,000, and 180,000 rpm. The luminal area was characterized via microscopy and image processing. The ground surface morphology and surface roughness at different rotational speeds were investigated. The results showed that a higher rotational speed led to a higher MRR and a smoother ground surface. This observation is significant for RA clinical guideline improvement.


2016 ◽  
Vol 1136 ◽  
pp. 311-316 ◽  
Author(s):  
Ke Wu ◽  
Naoki Yamazaki ◽  
Yutaro Ebina ◽  
Li Bo Zhou ◽  
Jun Shimizu ◽  
...  

Finishing process of sapphire wafer is meeting huge challenge to fulfill the strict requirement of high surface quality in semiconductor industry. Fixed abrasive process, although can guarantee the profile accuracy, leaves damaged layer on the surface or subsurface of sapphire wafer. Chemical mechanical polishing (CMP) is famous for providing great surface roughness, however, sacrifices surface geometrical accuracy. Therefore, a new chromium oxide (Cr2O3) sapphire grinding wheel based on chemical mechanical grinding (CMG) principle has been developed and its performance has also been put into examination. The experiment result has demonstrated that Cr2O3 possesses an outstanding potential in terms of a high material removal rate of sapphire wafer, meanwhile, largely reduces surface roughness from about 150nm to below 10nm in 1 hour. In addition, the design of experiment (DOE) has also been carried out to study the effect of influencing factors towards ultimate surface roughness of sapphire wafer. It reveals that the revolution speed of sapphire wafer bears twice greater influence towards surface roughness than the revolution speed of grinding wheel.


2010 ◽  
Vol 126-128 ◽  
pp. 995-1000 ◽  
Author(s):  
Hong Hua Su ◽  
Yu Can Fu ◽  
Jiu Hua Xu ◽  
Wen Feng Ding ◽  
Hong Jun Xu

The monolayer brazed diamond tools have recently been used increasingly in hard-brittle materials grinding because of their excellent grinding performances as long tool life, high material removal rate and large inter-grit chip space, etc. However, they possess an inherent shortcoming of the high roughness of the grinding surface. This work is an attempt to reduce the over-protruded grits of the monolayer brazed diamond wheel so that precision grinding operations can be executed effectively. In this investigation, the monolayer brazed diamond wheels with regular distribution pattern of grit have been dressed by a special conditioning process and used in precision grinding experiments on Li-Ti ferrite. The outcome of this attempt appeared highly encouraging. A substantial improvement of the ground surface roughness could be achieved with the dressed monolayer brazed diamond wheels.


2016 ◽  
Vol 679 ◽  
pp. 179-183
Author(s):  
Ze Qin Lin ◽  
Su Juan Wang ◽  
Xin Du Chen

Ultra-precision grinding is an effective method to machine the optical micro v-groove, which is one of microstructures applied to the fiber-optics connectors, displays and other photonics devices. The ultra-precision grinding technology directly obtains high surface quality for brittle materials when the grinding process is under the ductile mode. This paper introduces general aspects of ultra-precision grinding technology in the fabrication of the micro v-grooves structures and introduces the essential features of ultra-precision grinding. The process of the manufacturing of the optical micro v-grooves components is presented in this paper. It contains the prediction models of surface roughness and form accuracy in the ultra-precision grinding and the optimization model under the consideration of the influences of grinding parameters,grinder factors and the material properties on the surface quality and machining efficiency. This study therefore contributes to providing a further understanding on the mechanisms of material removal and surface generation in ultra-precision girnding.


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