• 한국공작기계학회논문집
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• 제15권5호
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• pp.51-58
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• 2006

The old technique of sandblasting which has been used for paint of scale removing, deburring and glass decorating has recently been developed into a powder blasting technique for brittle materials, capable of producing micro structures larger than $100{\mu}m$. Recently, this technique is applied to fabrication of the glass cap for OELD packaging. But, micro crack is generated on the blasted glass, which cause to decrease fracture strength. In this paper, we investigated the effect of blasting parameters on surface characteristics, surface shape and fracture strength of the powder blasted glass surface.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1102-1103
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• 2006

The pretreatment for substrate was carried out in change of gun pressure of $0.5\sim3.5$ bar using wet blasting. The size of $Al_2O_3$ powder was about $50{\sim}150{\mu}m$. As the results, the surface roughness of cemented carbide substrate was improved with increment of gun pressure of wet blasting. A new surface layer was formed and Co particles were uniformly distributed over the entire surface after pretreatment. The adhesion of the pretreated substrate in same PVD-TiAlN film was improved and in approximately $Ra=90\sim120\;nm$ shown the best adhesion value.

• 한국기계가공학회지
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• 제16권2호
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• pp.135-141
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• 2017

An experimental study of micro blasting for a rotating aluminum rod was conducted through the statistical analysis of ANOVA to obtain the effect of blasting conditions. The rotating equipment was designed and constructed with forward and backward moving for helical blasting, but rotation was used in this study. The blasting condition factors were the type of abrasive particle, nozzle diameter, pressure, standoff distance, injection time, etc. The width of the surface, the maximum depth of the sprayed surface, and ANOVA were analyzed by statistical analysis. The results showed that the contributions of the main factors were pressure, nozzle diameter, and injection particle.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1185-1189
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• 2007

In this paper, to improve the efficiency of pressurized pneumatic grit conveying for ship block open blasting process. Pressurized pneumatic grit conveying is defined as the transportation of grit(abrasive) in a compressed air flow. Total Pressure loss in flexible hose for pneumatic conveying is sum of pressure losses due to gas and grit and needle type pressure transmitter for measured pressure loss. haracteristics of grit open blasting by pneumatic conveying were studied experimentally. Studies variables were blasting nozzle ID, length and ID of flexible hose, grit flow rate, flow rate and pressure of transport air. It was experimentally proved that optimal open blasting condition and cost effective operation regarding grit blasting, obtaining a high qulity surface preparation(Sa $2^{\frac{1}{2}}$).

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.341-344
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• 2008

In order to study the effect of shot blasting condition on the formability of thin high strength steels, specimens were made by changing line speed of a commercial shot blasting plant with maintaining constant impeller condition. Surface roughness of prepared specimens was multiplied by lowering line speed or increasing density of shot impact. Formability was reduced as increasing shot impact. The elongation and stretching formability of shot blasted sheet were decreased by about 10% compared to original sheet. More significant decrease in bending formability was observed after shot blasting. This might be due to the concentrated impact near the surface where major strain occurs during bending process.

• 한국정밀공학회지
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• 제21권6호
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• pp.28-34
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• 2004

The old technique of sandblasting which has been used for decoration of glass surface has recently been developed into a powder blasting technique for brittle materials such as glass, silicon and ceramics, capable of producing micro structures larger than 100${\mu}{\textrm}{m}$. In this study, we introduced oblique powder blasting, and investigated the effect of the impacting angle of particles, the scanning times and the stand-off distance on the surface roughness and the weight-loss rate of samples with no mask, and the wall profile and overetching of samples with different mask pattern in powder blasting of soda-lime glass. The varying parameters were the different impact angles between 50$^{\circ}$ and 90$^{\circ}$, scanning times of nozzle up to 40 and the stand-off distances 70mm and 100mm. The widths of mask pattern were 0.2mm, 0.5mm and 1mm. The powder was alumina sharp particles, WA #600. The mass flow rate of powder during the erosion test was fixed constant at 175g/min and the blasting pressure of powder at 0.2Mpa.

• 화약ㆍ발파
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• 제41권4호
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• pp.41-50
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• 2023

본 연구에서는 굴착 물량 증대와 발파공해 저감을 위해서 전자뇌관을 이용한 수직방향 더블 데크 공법을 적용하였다. 더블 데크 공법은 상부 데크 발파 후 자유면이 완전히 형성되지 않은 상태에서 하부 데크 발파가 진행되면 발파 효율이 감소할 가능성이 있다. 이와 같은 이유로 더블 데크 공법은 데크 단차에 따라서 발파 효율이 달라진다. 따라서 본 연구에서는 홀 단차의 1~5배를 적용한 4가지 데크 단차를 제안하였고, 발파 후 파쇄도 분석을 통해 발파 효율을 평가하였다. 파쇄도 평가 결과 패턴 4(데크 단차=홀 단차×5)의 파쇄도가 가장 좋았으며, 패턴 3(데크 단차=홀 단차×3) 이상에서 파쇄효율이 큰 폭으로 증가하는 것을 확인할 수 있었다. 이에 따라 수직방향 더블 데크 발파 시 데크 단차는 최소 홀 단차의 3배 이상이 되어야 효율적인 발파 효과를 얻을 수 있다고 분석되었다.

• 환경위생공학
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• 제19권2호
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• pp.30-36
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• 2004

Dry decontamination technique is required for maintaining nuclear material handling equipment contaminated with highly radioactive material in a hot cell. In order to determine the optimum blasting conditions of dry ice pellet blasting device, the basic experiments have been conducted on the simulated test specimens of four types of metals. The removal efficiency of test piece was evaluated by the XRF analysis and the change of the surface condition before and after blasting. The removal efficiency of cesium on loose contamination was 100% under blasting pressure; 3 kg/$cm^2$, blasting distance; 10 cm, blasting time: 10 sec. In case of fixed contamination, the removal efficiency of cesium was almost 96% under blasting pressure; 4kg/$cm^2$, blasting distance; 10 cm, blasting time; 30 sec.

• Design & Manufacturing
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• 제14권1호
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• pp.36-41
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• 2020

Recently, due to the development of MEMS technology, researches for the production of effective micro structures and shapes have been actively conducted. However, the process technology based on chemical etching has a number of problems such as environmental pollution and time problems due to multi-process. Various processes to cope with this process are being studied, and one of the mechanical etching processes is the powder blasting process. This process is a method of spraying fine particles, which has the advantage of being an effective process in manufacturing hard brittle materials. However, it is also a process that adversely affects the material surface roughness and material properties due to the impact of the injection of fine particles. In this study, after fabricating micro-channels in fused silica glass with excellent optical properties among the hard brittle materials, we used the nano indentation system to analyze the micro parts using nano-particles as well as machinability and surface roughness analysis of the processed surface. The analysis was performed for the effective processing of powder blasting.

• Journal of Periodontal and Implant Science
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• 제38권1호
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• pp.67-74
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• 2008

Purpose: The aim of this study was to evaluate the effect of Er:YAG laser on microstructure and roughness of $TiO_2$ blasting implant surface. Materials and Methods: Ten $TiO_2$ blasting implant were used in this experiment. One implant was control group, and nine $TiO_2$ blasting implant surfaces were irradiated with Er:YAG laser under 100 mJ/pulse, 140 mJ/pulse, and 180 mJ/pulse condition for 1 min, 1.5 min, and 2 min respectively. Optical interferometer and scanning electron microscopy was utilized to measure roughness and microstructure of specimens. Results: The surface roughness was decreased after Er:YAG laser irradiation in all groups, but there was no significant difference. 100 mJ/pulse and 140 mJ/pulse group did not alter the $TiO_2$ blasting implant surface in SEM study while 180 mJ/pulse group altered the $TiO_2$ blasting implant surface. Implant surfaces showed melting, microfracture and smooth surface in 180 mJ/pulse group. Conclusion: Detoxification of implant surface using Er:YAG laser must be irradiated with proper energy output and irradiation time to prevent implant surface alteration.