Experimental evaluation of electrophoretic deposition-assisted polishing

Author(s):  
Hamed Adibi ◽  
Mohsen Khani ◽  
Hamed Esmaeili

The quest for precision in manufacturing sector is continuously evolving with the introduction of modern technologies and new techniques. In this research, the characteristics and influential parameters of a recently developed polishing process, known as electrophoretic deposition-assisted polishing (EPDAP), were investigated in external surface polishing of AISI 316 L stainless steel. The results revealed the improvement of surface roughness with increasing axial load up to the certain value of 11 N. The polishing time between 6 min and 12 min was recommended for polishing surfaces having a moderate initial roughness, close to 0.1 µm. Moreover, the increase of tool rotational speed led to the improvement of surface quality, while the variation of applied voltage had insignificant effects on the surface texture. In the second series of experiments, predictive equations of average surface roughness and material removal rate (MRR) were obtained based on analysis of variance. It was concluded that axial load and tool rotational speed are the most influential parameters on surface roughness and MRR, respectively. By performing a multi-response optimization, the optimum levels of control parameters at the same voltage of 15 V were calculated as axial load of 12 N, polishing time of 10 min, and tool rotational speed of 2000 rpm. This combination reduced the average surface roughness by 54.17% relative to the worst condition, which is characterized by the lowest axial loads, rotational speed, and polishing time at the design space. The maximum MRR of 3.975 mg/min was achieved at this optimum point. Assessment of the surface features indicated that the EPDAP process created uniform roughness profiles and resulted in an enhanced surface reflectance.

Author(s):  
MAHMUT ÇELIK ◽  
HAKAN GÜRÜN ◽  
ULAŞ ÇAYDAŞ

In this study, the effects of experimental parameters on average surface roughness and material removal rate (MRR) were experimentally investigated by machining of AISI 304 stainless steel plates by magnetic abrasive finishing (MAF) method. In the study in which three different abrasive types were used (Al2O3, B4C, SiC), the abrasive grain size was changed in two different levels (50 and 80[Formula: see text][Formula: see text]m), while the machining time was changed in three different levels (30, 45, 60[Formula: see text]min). Surface roughness values of finished surfaces were measured by using three-dimensional (3D) optical surface profilometer and surface topographies were created. MRRs were measured with the help of precision scales. The abrasive particles’ condition before and after the MAF process was examined and compared using a scanning electron microscope. As a result of the study, the surface roughness values of plates were reduced from 0.106[Formula: see text][Formula: see text]m to 0.028[Formula: see text][Formula: see text]m. It was determined that the best parameters in terms of average surface roughness were 60[Formula: see text]min machining time with 50[Formula: see text][Formula: see text]m B4C abrasives, while the best result in terms of MRR was taken in 30[Formula: see text]min with 50[Formula: see text][Formula: see text]m SiC abrasives.


2016 ◽  
Vol 1136 ◽  
pp. 490-493 ◽  
Author(s):  
Min Li ◽  
Bing Hai Lyu ◽  
Ju Long Yuan ◽  
Ping Zhao

Shear-thickening polishing (STP) technology was used on ultraprecision machining of Si3N4 ceramics. The STP slurry with diamond abrasives was prepared for STP process and its rheological property was studied. The polishing performance of Si3N4 ceramics with STP was analyzed. Results show that STP slurry with diamond abrasives exhibits non-Newtonian power-law fluid characteristics with shear-thickening effect. As using STP slurry with abrasive particle size of 0.2 μm, the material removal rate changed from 4.22 to 4.05 μm/h after 60 mins ́ polishing; and decreased from 3.88 to 3.75 μm/h after 120 mins ́ polishing. The average surface roughness reduced from Ra 107.2 to Ra 6.5 nm after 120 mins ́ polishing.


2012 ◽  
Vol 622-623 ◽  
pp. 51-55
Author(s):  
Ushasta Aich ◽  
Amit Kumar Pal ◽  
Dipak Laha ◽  
Simul Banerjee

Simultaneous optimization of conflicting type responses like material removal rate (MRR) and average surface roughness (Ra) in stochastic type electrical discharge machining (EDM) process is a matter of concern to the process engineers. In this paper, EDM is first modeled by response surface methodology (RSM). Current setting, pulse on time and pulse off time were taken as the input parameters while material removal rate and average surface roughness as the responses. Multi-objective simulated annealing (MOSA) is then applied on these models. Pareto optimal solution set is thus developed. It would assist a process engineer to take decision regarding the optimal setting of the process parameters for a specific need-based requirement.


1989 ◽  
Vol 111 (4) ◽  
pp. 315-321 ◽  
Author(s):  
R. J. Wallace ◽  
S. M. Copley

In this research, the feasibility of shaping Si3N4 by overlapping multiple grooves produced with a continuously operated CO2 laser beam is demonstrated. The relationships of process parameters such as material removal rate and arithmetic average surface roughness to machine parameters such as feed and speed have been investigated. Strategies for laser shaping are discussed and an economic evaluation of laser shaping is presented.


2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110118
Author(s):  
Zenan Chu ◽  
Tao Wang ◽  
Qiang He ◽  
Kai Zhao

To solve the problems of low processing efficiency and poor glass surface quality when using rare earth polishing powder to grind super-hard K9 glass. The potential, phase structure, surface morphology, and particle size distribution of the nano-rare earth polishing powder were characterized. Compare the evaluation indexes such as polishing efficiency, surface morphology, and contact angle after the polishing process is changed. The results of the comparative study show that the average surface roughness of the glass after heating ultrasonic polishing process is 0.9064 nm, the polishing rate reaches 0.748 μm/min, the average surface roughness of the glass without heating ultrasonic polishing process is 1.3175 nm, and the polishing rate reaches 0.586 μm/min, the ultrasonic assisted polishing process is superior to the conventional polishing process. The heating ultrasonic method provides experimental basis for precise and rapid processing.


2014 ◽  
Vol 627 ◽  
pp. 29-34 ◽  
Author(s):  
Vichaya Thammasing ◽  
Somkiat Tangjitsitcharoen

The purpose of this research is to develop the models to predict the average surface roughness and the surface roughness during the in-process grinding by monitoring the cutting force ratio. The proposed models are developed based on the experimentally obtained results by employing the exponential function with four factors, which are the spindle speed, the feed rate, the depth of cut, and the cutting force ratio. The experimentally obtained results showed that the dimensionless cutting force ratio is usable to predict the surface roughness during the grinding process, which can be calculated and obtained by taking the ratio of the corresponding time records of the cutting force Fy in the spindle speed direction to that of the cutting force Fz in the radial wheel direction. The multiple regression analysis is utilized to calculate the regression coefficients with the use of the least square method at 95% confident level. The experimentally obtained models have been verified by the new cutting tests. It is proved that the developed surface roughness models can be used to predict the in-process surface roughness with the high accuracy of 93.9% for the average surface roughness and 92.8% for the surface roughness.


2015 ◽  
Vol 2015 (DPC) ◽  
pp. 001928-001955
Author(s):  
Naoya Watanabe ◽  
Masahiro Aoyagi ◽  
Daisuke Katagawa ◽  
Tsubasa Bandoh ◽  
Takahiko Mitsui ◽  
...  

Three-dimensional integrated circuits (3D-ICs) using through silicon via (TSV) have been developed as an emerging technology that can lead to significant progress (1–4). Among various TSV processes, the via-middle process has potential for wide spread use because formation of small-sized TSVs is relatively easy in the via-middle process. However, TSV reveal process must be performed for electrical contact in the via-middle process. This TSV reveal process is important because it can influence the metal contamination and stacking yield of 3D-ICs. Conventionally, TSV reveal is performed by Si grinding and Si dry etching (5). A disadvantage of that method is the resultant TSV depth deviation, which can cause bonding failure during wafer/chip stacking. In (6), TSV leveling was performed by introducing a chemical mechanical polishing (CMP) step after deposition of the backside insulator. However, the revealed TSVs break during CMP step if they exceed a certain height. To overcome these problems, we developed a novel TSV reveal process comprising direct Si/Cu grinding and metal contamination removal (7,8). First, simultaneous grinding of Cu and Si was performed using a novel vitrified grinding wheel. In situ cleaning with a high-pressure micro jet and the inelastic porous structure of the grinding wheel suppressed the adhesion of Cu contaminants to the Si, and TSVs were leveled and exposed. Next, an electroless Ni-B film was deposited on the Cu surface of the TSVs. The Si was etched with an alkaline solution, whereas the Cu was protected by the Ni-B film. An insulator was deposited, and then the insulator on the top surface of the TSV was removed. We achieved the backside reveal of TSVs without TSV depth deviation and suppressed Cu contamination to less than 1e11 atoms/cm2. However, after direct Si/Cu grinding with an 8000 grit grinding wheel, the average surface roughness of Si was 5–10 nm, which is larger than that after chemical mechanical polishing (CMP). In this paper, we developed vitrified grinding wheels with very high grit numbers (#30,000 and #45,000) and present an improved version of our TSV reveal process. The average surface roughness of Si after Si/Cu grinding was approximately 3 nm for the 30,000 grit grinding wheel and 1 nm for the 45,000 grit grinding wheel. This value is equivalent to that after CMP. The improved process produced a uniform reveal of 4-um-diameter TSVs without TSV depth deviation and Cu contamination. The Cu contaminant concentration on Si region between TSVs was small (<3e10 atoms/cm2). This process will reduce the cost of the TSV reveal process and considerably improve the TSV yield.


2019 ◽  
Vol 89 (5) ◽  
pp. 742-750
Author(s):  
İrem Kurt ◽  
Zafer Cavit Çehreli ◽  
Ayça Arman Özçırpıcı ◽  
Çağla Şar

ABSTRACT Objectives: To determine the best bonding method of orthodontic attachment among monolithic zirconia, feldspathic porcelain, hybrid porcelain, and the impact of surface-conditioning methods using a three-dimensional optical profilometer after debonding. Materials and Methods: 56 feldspathic porcelain, 56 monolithic zirconia, and 56 hybrid porcelain samples were divided into four surface treatment subgroups: (1) hydrofluoric (HF) acid etch + silane, (2) Al2O3 sandblasting + silane, (3) silicoating (SiO2), and (4) diamond bur + silane. The specimens were tested to evaluate shear bond strength (SBS). Residual composite was removed after debonding. Three-dimensional white-light interferometry was used to obtain quantitative measurements on surface roughness. Results: The highest SBS value was found for the HF acid–etched feldspathic porcelain group. The average surface roughness values were significantly higher in all material groups in which diamond bur was applied, while roughening with Cojet provided average surface roughness values closer to the original material surface. Conclusions: Variations in structures of the materials and roughening techniques affected the SBS and surface roughness findings.


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