scholarly journals Utilization of Secondary Jet in Cavitation Peening and Cavitation Abrasive Jet Polishing

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 86
Author(s):  
Hao Pang ◽  
Gracious Ngaile

The cavitation peening (CP) and cavitation abrasive jet polishing (CAJP) processes employ a cavitating jet to harden the surface or remove surface irregularities. However, a zero incidence angle between the jet and the surface limits the efficiency of these two processes. This limitation can be improved by introducing a secondary jet. The secondary jet interacts with the main jet, carrying bubbles to the proximity of the workpiece surface and aligning the disordered bubble collapse events. Through characterizing the treated surface of AL6061 in terms of the hardness distribution and surface roughness, it was found out that the secondary jet can increase the hardening intensity by 10%, whereas the material removal rate within a localized region increased by 66%. In addition, employing multiple secondary jets can create a patched pattern of hardness distribution. Another finding is that the hardening effect of the cavitation increases with the processing time at first and is then saturated.

2010 ◽  
Vol 34 (2) ◽  
pp. 295-308 ◽  
Author(s):  
Akram Saad ◽  
Robert Bauer ◽  
Andrew Warkentin

This paper investigates the effect of both single-point and diamond-roll dressing techniques on the workpiece surface roughness in grinding. Two empirical surface roughness models are studied – one that incorporates single-point dressing parameters, and another that incorporates diamond-roll dressing parameters. For the experimental conditions used in this research, the corresponding empirical model coefficients are found to have a linear relationship with the inverse of the overlap ratio for single-point dressing and the interference angle for diamond-roll dressing. The resulting workpiece surface roughness models are then experimentally validated for different depths of cut, workpiece speeds and dressing conditions. In addition, the models are used to derive a relationship between overlap ratio for single-point dressing, and interference angle for diamond-roll dressing such that both dressing techniques produce a similar surface finish for a given material removal rate.


Author(s):  
Fred L. Amorim

The AISI P20 steel is applied by the tooling industry as material for injection molding tools. It is known that the EDM process parameters technology installed at the majority of CNC EDM machines do not cover some of the necessities of the tooling industry. So, the customers are required to develop their own process parameters. In order to provide useful technical information to the industry an experimental investigation on the EDM of the AISI P20 tool steel under finish machining has been carried out. The material removal rate Vw, volumetric relative wear v and workpiece surface texture Ra, which are representative of EDM performance aspects, were analyzed against the variation of some of the most important EDM electrical variables using copper tool electrodes under positive and negative polarity. The EDM machine generator was also programmed to actuate under isoenergetic mode and relaxation mode. The results are discussed and some appropriate parameters for EDM of AISI P20 are suggested.


2016 ◽  
Vol 851 ◽  
pp. 149-154
Author(s):  
Zhen Gang Wu ◽  
Dong Shan He ◽  
Ping Zhou ◽  
Dong Ming Guo

Accurate prediction of the material removal rate (MRR) distribution is very important for the control of the polishing process. However, the widely used prediction method of MRR based on the Preston equation is still incapable of predicting the roll-off phenomenon in polishing process. One of the reasons is that many of the researchers’ neglected the effect of the surface profile of the workpiece on the MRR. In this paper, the evolutionary process of MRR distribution with the change of surface profile using two different polishing pad is studied, it is found that MRR varies gradually with the change of surface profile and tends to be uniform finally. Based on the analysis of contact pressure considering the actual surface profile of workpiece and modified Preston equation, the distribution of MRR is analyzed. It is found that the Preston coefficient distribution on workpiece surface is stable when the surface profile variation is small and shows obvious differences from the center to the edge of the workpiece. Through the comparison it is found that correlation between the regularities of Preston coefficient distribution and the type of polishing pad is significant. The research results in this paper will play an important guiding role in the quantitative prediction method research of polishing process.


2010 ◽  
Vol 447-448 ◽  
pp. 268-271 ◽  
Author(s):  
Yuna Yahagi ◽  
Tomohiro Koyano ◽  
Masanori Kunieda ◽  
Xiao Dong Yang

This paper describes machining characteristics of high spindle speed WEDG using the electrostatic induction feeding method. In this method, non-contact electric feeding allows the workpiece rod to be rotated at a high speed of up to 50000rpm. Since the temperature rise on the workpiece surface is low, the material removal rate was two times higher and the surface roughness was also improved compared to the normal RC discharge circuit where the rotational speed was 1000rpm at the highest due to contact electric feeding using a brush. Furthermore, micro rods thus prepared were used as tool electrodes to machine micro-holes with the same rotation speed of 50000rpm. It was found that smaller gaps and better straightness can be obtained due to the high flushing efficiency at the high spindle speed.


Author(s):  
Xiaokang Chen ◽  
Jianping Zhou ◽  
Kedian Wang ◽  
Yan Xu

Short electric arc machining is a recently developed high-efficiency electrical discharge machining technology. Material removal rate, tool mass wear ratio ([Formula: see text]), and workpiece surface roughness ( Ra) are important indexes used to evaluate the machining performance of short electric arc machining. In order to obtain better machining effect, the nickel-based superalloy GH4169 is machined by graphite in this article. The influence of voltage, duty cycle, and flushing pressure on short electric arc machining performance is then investigated under different tool polarity conditions. Experimental results show that higher material removal rate and lower [Formula: see text] can be obtained by negative polarity machining, while positive polarity machining can produce better surface quality. To investigate the cause of this difference, the surface integrity of GH4169 machined by different tool polarity is studied from macro and micro perspectives.


2016 ◽  
Vol 834 ◽  
pp. 96-101 ◽  
Author(s):  
Vasile Merticaru ◽  
Andrei Mihalache ◽  
Gheorghe Nagîţ ◽  
Oana Dodun ◽  
Laurenţiu Slătineanu

One of the machining methods able to ensure a high material removal rate in the case of obtaining threaded surfaces is the whirling machining. In order to obtain a high accuracy of the machined surface and low values of the surface irregularities, an adequate selection of the machining parameters is necessary. A geometrical analysis of generating the surfaces in case of applying the whirl threading was developed. Geometrical and kinematical conditions were considered and software was used in order to modelling the process and to highlight the influence exerted by some process input factors on the machining errors and height of the surface irregularities.


2014 ◽  
Vol 1017 ◽  
pp. 92-97 ◽  
Author(s):  
Die Zhang ◽  
Yun Huang ◽  
Xian Yin ◽  
Li Qi Zhou ◽  
Yu Hang Yang ◽  
...  

Abrasive belt grinding experiments of ZrO2Engineering Ceramics are carried out by using 4 different abrasive belts. The orthogonal test with zirconia-corundum belt was to get the best grinding parameter, the amount of material removal workpiece surface roughness and belt wear were measured to get the best grinding parameter.In this paper,the influence of abrasive belt granularity and different grinding parameters to grinding efficiency and workpiece surface quality throughout the process of grinding ZrO2Engineering Ceramics was analyzed. Analysis wear mechanism of engineering ceramics based on the Abrasive cutting model by observing the surface morphology. The results show that increasing the grinding force or the abrasive belt granularity can decrease the workpiece surface roughness;With the abrasive belt speed or grinding force increasing,the material removal rate and the wear ratio to some extent, but brittle fracture is occued easily on its surface when exceeds the critical value; When the abrasive belt speed is 19m/s,the grinding force is 15N and the abrasive belt granularity is 120#, ZrO2Engineering Ceramics grinding effects reach the best.


Author(s):  
Zohreh Mohammadi ◽  
Mohammad R. Movahhedy

Chatter is a limiting factor in machining systems with adverse effects for workpiece surface, tool and machine life and material removal rate. Proper modelling of this phenomenon requires that the dynamic characteristics of the machining system is known. It is common to obtain the dynamic of the system by modal tests in stationary condition. However, the vibration characteristics of a machine change between its operating and resting mode. The goal of this work is to study vibrations in boring using the vibrational characteristic in operational conditions using the operating deflection shape method. In this paper, vibration characteristics of the in the boring bar is obtained by both modal analysis and operating deflection shape methods and the results are compared. The results show that differences exist between the two conditions that can be small or large in different machining conditions.


2008 ◽  
Vol 389-390 ◽  
pp. 289-294
Author(s):  
Manabu Iwai ◽  
Wen Qiu Wei ◽  
Shinichi Ninomiya ◽  
Sadao Sano ◽  
Tetsutaro Uematsu ◽  
...  

In order to realize electrochemical finishing in tap water, an ultrasonic vibration using a transducer enabling three kinds of vibration modes, i.e., axial, bending, and complex, was given to the electrode. During the test finishing, it was observed that with electrode without ultrasonic vibration, the workpiece surface was simply covered with the rust. On the contrary, by applying the ultrasonic vibration of bending vibration mode or complex vibration mode with an appropriate amplitude, the material removal rate was increased and the surface roughness was improved.


2010 ◽  
Vol 154-155 ◽  
pp. 1739-1743
Author(s):  
Wei Li ◽  
Qian Jun Tian

In this paper, the mechanism of Electrolysis In-process Dressing (ELID) lapping process using new BCB (bamboo charcoal bonded) abrasive wheel is researched. Some experiments of machining for silicon wafers were carried out for exploring the effect of some machining process parameters on material removal rate and surface roughness. Experiments show that: Material removal rate and machined workpiece surface roughness are increased with increase of the lapping wheel’s rotation speed and processing loading; The machined workpiece surface quality is affected with the lapping wheel surface condition, due to the abrasives are trued by electrolysis dressing in the lapping process, therefore the BCB lapping wheel always keeps better machining condition to obtain excellent machined workpiece surface quality efficiently.


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