Effects of Processing Parameters of Oxide Layer in Ultrasonic Vibration and Electrolytic In-Process Dressing Combined Grinding

2014 ◽  
Vol 1027 ◽  
pp. 3-7
Author(s):  
Bo Zhao ◽  
Xiao Feng Jia

In order to study the states of oxide layer under different pre-dressing process conditions in ultrasonic vibration and electrolytic in-process dressing combined grinding. The effects of electrical parameters, wheel speed, ultrasonic vibration on the oxide layer are investigated with indicators of oxide layer surface morphology and thickness characteristics. The results indicate that the oxide layer thickness increases with the decrease of inter-electrode gap and the increase of duty ratio with pre-dressing time. The effect of ultrasonic vibration cause thinning of the oxide layer. Oxide layer surface morphology allowing processing requirements are obtained by duty cycle of 5μs: 5μs, electrode gap of 0.3mm, wheel speed of 3200 r/min.

2006 ◽  
Vol 532-533 ◽  
pp. 588-591 ◽  
Author(s):  
Bao Ji Ma ◽  
Yu Quan Zhu ◽  
D.J. Stephenson

The purpose of this experimental research are investigation the growth behaviors of the oxide layer at different pre-dressing conditions in ELID pre-dressing, effects of voltage and duty ratio of the power supply, wheel speed on the oxide layer formation characteristics on the metal bond diamond wheel surface. The results indicated that the oxide layer thickness on the wheel surface increase with pre-dressing time. The oxide layer growth rate is faster in beginning period time of pre-dressing process then slow down. Both the thickness and growth rate of oxide layer increase with the increase of duty ratio and applied voltage. It takes longer time for oxide layer growth rate to reach to stable state in lower duty ratio condition than in higher duty ratio condition. There are no effects of wheel speed on oxide layer growth behaviors in the wheel speed range of 1000rpm to 4000 rpm.


2013 ◽  
Vol 815 ◽  
pp. 86-92
Author(s):  
Xiao Feng Jia ◽  
Bo Zhao ◽  
Ping Yan Bian

The oxide layer formed and removed on the surface of the grinding wheel has a significant influence on the grinding quality of ultrasonic-ELID multiplicate grinding. In this paper on the basis of the principles of electrochemical and ultrasonic vibration, the mechanisms of oxide layer formation and remotion were analyzed. Then, the predictive modeling of oxide layer thickness was proposed. The effects of main factors on the oxide film thickness were simulated and analyzed theoretically. The simulation results show that the layer thickness decreases with the decrease of the duty ratio or the grain volume ratio or the ultrasonic frequency ,and the increase of the electrode gap during the composite grinding process.


2014 ◽  
Vol 528 ◽  
pp. 8-13
Author(s):  
Jian Jun Xi ◽  
Jun Zhao ◽  
Zhi Gang Wang ◽  
Chun Ping Zhao ◽  
Mei Ping Xue

This article presents a detailed research on pulse electrical parameters for non-cyanide electroplating copper plating on stainless still substrate. The study was made about the effect of the current density, duty ratio and frequency on the surface morphology, thickness and uniformity of the deposited layers. The surface morphology was examined by MIT 300 metallurgical microscope and the thickness of copper coatings was examined by TT260 coating thickness gauge. Current density 0.4A/dm2 is the optimum current at which the best uniform coating can be formed.


2015 ◽  
Vol 22 (03) ◽  
pp. 1550035 ◽  
Author(s):  
WEI-YUAN YU ◽  
SEN-HUI LIU ◽  
XIN-YA LIU ◽  
JIA-LIN SHAO ◽  
MIN-PEN LIU

In this study, Sn - Ag - Ti ternary alloy has been used as the active solder to braze pure aluminum and graphite in atmospheric conditions using ultrasonic vibration as an aid. The authors studied the formation, composition and decomposition temperature of the surface oxides of the active solder under atmospheric conditions. In addition, the wettability of Sn -5 Ag -8 Ti active solder on the surface of pure aluminum and graphite has also been studied. The results showed that the major components presented in the surface oxides formed on the Sn -5 Ag -8 Ti active solder under ambient conditions are TiO , TiO 2, Ti 2 O 3, Ti 3 O 5 and SnO 2. Apart from AgO and Ag 2 O 2, which can be decomposed at the brazing temperature (773 K), other oxides will not be decomposed. The oxide layer comprises composite oxides and it forms a compact layer with a certain thickness to enclose the melted solder, which will prevent the liquid solder from wetting the base metals at the brazing temperature. After ultrasonic vibration, the oxide layer was destroyed and the liquid solder was able to wet and spread out around the base materials. Furthermore, better wettability of the active solder was observed on the surface of graphite and pure aluminum at the brazing temperature of 773–823 K using ultrasonic waves. The ultrasonic wave acts as the dominant driving factor which promotes the wetting and spreading of the liquid solder on the surface of graphite and aluminum to achieve a stable and reliable brazed joint.


2009 ◽  
Vol 615-617 ◽  
pp. 113-116 ◽  
Author(s):  
Kazutoshi Kojima ◽  
Hajime Okumura ◽  
Kazuo Arai

We have carried out detailed investigations on the influence of the growth conditions and the wafer off angle on the surface morphology of low off angle homoepitaxial growth. We found triangular features to be also serious problems on a 4 degree off 4H-SiC Si-face epitaxial layer surface. The control of the C/Si ratio by controlling the SiH4 flow rate is effective in suppressing the triangular features on 4 degree off Si-face homoepitaxial layer. As regards epitaxial growth on a vicinal off-axis substrate, the small off angle difference of a tenth part of a degree has an influence on the surface morphology of the epitaxial layer. This tendency depends on the face polarity and a C-face can be obtained that has a specular surface with a lower vicinal off angle than a Si-face. By controlling this off angle, a specular surface morphology without a bunched step structure could be obtained on a vicinal off angle 4H-SiC Si-face.


1996 ◽  
Vol 460 ◽  
Author(s):  
Jinmin Chen ◽  
W. E. Frazier ◽  
E. V. Barrera

ABSTRACTIn an effort to expand the composition range over which Al3Ti is stable, various amounts of niobium were substituted for titanium and processed by melt-spinning. Several samples were annealed both at 600°C and 1000°C for 24 hours. The effects of processing parameters such as wheel speed, the amount of niobium, and annealing temperatures on the structure were investigated by XRD and EXAFS. XRD showed that for all the samples the only structure present was DO22-The DO22 structure was stable even after the high temperature heat treatments. By means of EXAFS, niobium atoms were observed to occupy titanium sites in the DO22 structure. Furthermore, in the unannealed samples, increasing wheel speed of the melt spinning process or the niobium concentration tended to distort the crystal structure. It was observed that Ti EXAFS had different results from the Nb EXAFS beyond their occupying similar sites, which suggested there may exist some composition zones, i.e. rich Nb zone or rich Ti zones, although the structures present were still DO22. The samples were found to experience different distortions as a function of annealing temperatures.


2013 ◽  
Vol 699 ◽  
pp. 133-137 ◽  
Author(s):  
Byeong Woo Lee ◽  
Jin Heui Koo ◽  
Tae Suk Lee ◽  
Yun Hae Kim ◽  
Jae Suk Hwang

Zinc oxide (ZnO) powders were synthesized by a simple precipitation and a hydrothermal process at the temperature range RT-100°C. In precipitation process, the powders were formed by mixing aqueous solutions of zinc nitrate with NaOH aqueous solution under controlled process conditions such as precursor concentration, reaction pH and temperature. Single phase ZnO particles can be easily synthesized in lower precursor concentration, higher reaction pH and temperature. The powders synthesized at room temperature exhibited plates, rods or pointed multipod morphologies depending on the concentration and pH. ZnO crystallites synthesized by hydrothermal process consisted mostly of well developed large or elongated crystallites of plates or rods in shape. The results reveal that the ZnO crystallite sizes and shapes would be efficiently controllable by changing the processing parameters of the preparation processes.


2018 ◽  
Vol 777 ◽  
pp. 300-305
Author(s):  
Kasem Charoenrut ◽  
Chaiyasit Banjongprasert

Aluminum-Silicon Alloy, ADC12 is one of the most popular alloys for pressure die casting due to its high castability and high productivity. ADC12 is a hypoeutectic aluminum-silicon alloy that contains 10-12wt% of Si and has an occasional problem for a mechanical properties failure such as crack and shrinkage porosity. This study presents the investigation of the microstructure of ADC12 parts produced by pressured die casting with different process parameters and chemical compositions. The microstructure was observed using optical microscopy (OM) and scanning electron microscopy (SEM) with energy – dispersive X-ray (EDX) and electron backscatter diffraction (EBSD) to determine phases, grain, and crystallographic information in order to understand the microstructural evolution after die casting with different process conditions. Changes in casting pressure and a reduction of iron content contributed to enhanced mechanical properties and less shrinkage porosity. This was due to different processing parameters, mainly casting pressure. The average grain size of aluminum matrix was also reduced due to a higher pressure during casting with a moderately fast cooling rate.


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