• Title/Summary/Keyword: base material

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Graphic Simulation of Material Removal Process Using Bounding Box and Base Plane (기준평면과 경계상자를 이용한 NC 절삭과정의 그래픽 시뮬레이션)

  • 이철수;박광렬
    • Korean Journal of Computational Design and Engineering
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    • v.2 no.3
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    • pp.161-174
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    • 1997
  • In this paper, the techniques for graphic simulation of material removal process are described. The concepts of the bounding box and base plane are proposed. With these concepts, a real-time shaded display of a Z-map model being milled by a cutting tool following an NC path can be implemented very efficiently. The base planes make it possible to detect the visible face of Z-map model effectively. And the bounding box of tool sweep volume provides minimum area of screen to be updated. The proposed techniques are suitable for implementation in raster graphic device and need a few memories and a small amount of calculation. Proposed method is written in C and executable on MS-Windows95 and Window-NT.

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Dissolution Characteristics of ph-Dependent Antacid Granules Agglomerated in High Speed Agitation Type Speed Agitation Type Granulator

  • Choi, Woo-Sik;Lee, Jung-Sun
    • Archives of Pharmacal Research
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    • v.18 no.5
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    • pp.314-319
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    • 1995
  • Antacid granules were prepared by agglomeration and powder method in high speed agitation type granulator. The copmositions of the test antacids were sodium bicarbonate nad magnesium carbonate nad a coating material was powder of polyvinylacetal diethyl-aminocacetate (AEA) and an additive material was talc powder. The dissolution characteristics of base from the antacid granules were investigated to evaluate neutralization capacity of hydrochloric profile of base and neutralization behavior, the following results were obtained : The prepared granules showed a pH-dependent dissolution pattern of a base. The dissolution profile of a base was varied with addition of talc powder as well as coating amount of AEA. The relationship between the ratio of dissolution retarded time for 20% and 10% AEA. The relationship between the ratio of dissolution retarded time for 20% AEA coated granules $\theta_{20}/\theta_{10}$ and the diameter reduction of the granules was explained by the rate process of neutralization of hydrochloric acid.

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Diamond Crystal Growth Behavior by Hot Filament Chemical Vapor Deposition According to Pretreatment Conditions

  • Song, Chang Weon;You, Mi Young;Lee, Damin;Mun, Hyoung Seok;Kim, Seohan;Song, Pung Keun
    • Journal of the Korean institute of surface engineering
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    • v.53 no.5
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    • pp.241-248
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    • 2020
  • The change of the deposition behavior of diamond through a pretreatment process of the base metal prior to diamond deposition using HFCVD was investigated. To improve the specific surface area of the base material, sanding was performed using sandblasting first, and chemical etching treatment was performed to further improve the uniform specific surface area. Chemical etching was performed by immersing the base material in HCl solutions with various etching time. Thereafter, seeding was performed by immersing the sanded and etched base material in a diamond seeding solution. Diamond deposition according to all pretreatment conditions was performed under the same conditions. Methane was used as the carbon source and hydrogen was used as the reaction gas. The most optimal conditions were found by analyzing the improvement of the specific surface area and uniformity, and the optimal diamond seeding solution concentration and immersion time were also obtained for the diamond particle seeding method. As a result, the sandblasted base material was immersed in 20% HCl for 60 minutes at 100 ℃ and chemically etched, and then immersed in a diamond seeding solution of 5 g/L and seeded using ultrasonic waves for 30 minutes. It was possible to obtain optimized economical diamond film growth rates.

Effect of surface treatment on shear bond strength of relining material and 3D-printed denture base

  • Park, Se-Jick;Lee, Joon-Seok
    • The Journal of Advanced Prosthodontics
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    • v.14 no.4
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    • pp.262-272
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    • 2022
  • PURPOSE. This study aimed to analyze the shear bond strength between the 3D-printed denture base and the chairside relining material, according to the surface treatment. MATERIALS AND METHODS. Cylindrical specimens were prepared using DENTCA Denture Base II. The experimental groups were divided into 6 (n = 10): no surface treatment (C), Tokuyama Rebase II Normal adhesive (A), sandblasting (P), sandblasting and adhesive (PA), sandblasting and silane (PS), and the Rocatec system (PPS). After bonding the chairside relining material to the center of the specimens in a cylindrical shape, they were stored in distilled water for 24 hours. Shear bond strength was measured using a universal testing machine, and failure mode was analyzed with a scanning electron microscope. Shear bond strength values were analyzed using one-way analysis of variance, and Tukey's honest significant difference test was used for post-hoc analysis (P < .05). RESULTS. Group PPS exhibited significantly higher shear bond strength than all other groups. Groups P and PA displayed significantly higher bond strengths than the control group. There were no significant differences between groups PS and A compared to the control group. Regarding the failure mode, adhesive failure occurred primarily in groups C and A, and mixed failure mainly in groups P, PA, PS, and PPS. CONCLUSION. The shear bond strength between the 3D-printed denture base and the chairside relining material exhibited significant differences according to the surface treatment methods. It is believed that excellent adhesive strength will be obtained when the Rocatec system is applied to 3D-printed dentures in clinical practice.

A study on the fracture toughness degradation in cryogenic structural material using single-specimen method (단일 시험편법에 의한 극저온용 구조재료의 파괴인성 저하에 관한 연구)

  • Kwon, Il-hyun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.2
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    • pp.343-351
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    • 1998
  • This paper was investigated degradation of the fracture toughness caused by sensitizing heat-treatment of the cryogenic structural material JN1 base metal using unloading compliance method reported as useful a method in evaluating the elastic-plastic fracture toughness at cryogenic temperature. The specimens used in this paper were 20% side-grooved 0.5T-CT specimens which were machined in the JN1 base metal. Also, to investigate cryogenic fracture toughness of the fusion line region in the JN1 GTA weldments, it was also used 20% side-grooved 0.5T-CT specimens that was machined fusion line to located in the middle of the specimen. The cryogenic fracture toughness values of the JN1 base metal were significantly decreased with increasing the time and temperature of the heat treatment. The fracture toughness value obtained from the fusion line specimen was invalid, but it was lower value than that of the JN1 base metal. Especially, this value was approximately equal with that obtained from the JN1 650.deg. C-5h heat-treated material.

Hardness Distribution and Microstructures of Electric Resistance Spot Welded 1GPa Grade Dual Phase Steel (1GPa급 DP강 전기저항점용접부의 경도분포와 미세조직의 상관관계)

  • Na, Hye-Sung;Kong, Jong-Pan;Han, Tae-Kyo;Chin, Kwang-Geun;Kang, Chung-Yun
    • Journal of Welding and Joining
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    • v.30 no.2
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    • pp.76-80
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    • 2012
  • In this study, the effect of the welding current on the hardness characteristics and microstructure in the resistance spot welding of 1GPa grade cold-rolled DP steel was investigated, Also, correlation between the hardness and microstructure was discussed. In spite of the change in the welding current, the hardness distributions near weld was similar. the hardness in the HAZ and the fusion zone was higher than that of the base metal and the hardness in the fusion zone was variated with the location. Especially, the hardness of HAZ adjacent to the base metal showed maximum value, and softening zone in the base metal adjacent to HAZ was found. With the increasing of welding current, there were no difference in maximum hardness and average hardness in the fusion zone were, but the hardness of the softening zone reduced. The difference in the hardness in each location of weld due to grain size of prior austenite. The softening of the base metal occurred by tempering of the martensite.

The Fatigue Behavior of Laser Welded Sheet Metal (레이저 용접 판재의 피로거동)

  • 오택열
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.10a
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    • pp.339-344
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    • 1999
  • For the Tailor Welded Blank sheet used for automobile body panel, the characteristics of fatigue strength and crack propagation behavior were studied. The thickness of specimen was machined to be same (0.9mm+0.9mm) and different (0.9mm+2.0mm). As a base test, mechanical properties around welding zone were examined. The results indicated that there were no significant decreases in mechanical properties, but hardness around welding bead is 2.3 times greater than base material. The fatigue strength was the highest when the loading direction was parallel to the welding direction, which was about 85% of tensile strength of base material. It was decreased by 8.5% when the thickness of specimen and base material was different, and it is increased by 25% when pre-strain was applied. The crack propagation rate was noticeable decreased around welding line and rapidly increased as it passed by welding line. Reviewing the shape of the crack propagation, crack width around welding line was wide around the welding zone due to retardation of crack growth, but it became narrow passing welding line due to decreased toughness.

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Effect of Hot-stamping Heat Treatment on Microstructure and Hardness in TWB Laser Joints of Al-Si-coated Boron Steel and Zn-coated DP Steel (Al-Si 도금된 보론강과 Zn 도금된 DP강의 TWB 레이저 용접부 미세조직과 경도에 미치는 핫 스탬핑 열처리의 영향)

  • Jung, Byung-Hun;Kong, Jong-Pan;Kang, Chung-Yun
    • Korean Journal of Metals and Materials
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    • v.50 no.3
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    • pp.224-232
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    • 2012
  • In this study, the effect of hot-stamping heat treatment on the microstructure and hardness of TWB(Tailor Welded Blank) laser joints in Al-Si-coated boron steel and Zn-coated DP(Dual Phase)590 steel was investigated. In the TWB joints without heat treatment, hardness profiles showed local hardness deviation near the fusion zone. However, there was no hardness deviation in the heat treated specimen and its hardness was higher than that of the one without the heat treatment, due to a fully martensite microstructure. In the TWB joints of both the boron and DP steels, the maximum hardnesses were observed at the HAZ(Heat Affected Zone) near the base metal, and the hardness decreased gradually to the base metal. In the heat treated joints, the hardnesses of the HAZ and the base metal of the boron steel side were similar to the maximum hardness of the weld, while those of the HAZ and the base metal of the DP steel side were higher than the maximum hardness.

Base Pattern Development of Protective Clothing - Focusing on Protective Clothing for Riot Policewomen - (보호복 상의 베이스 패턴 개발 - 여경보호복을 중심으로 -)

  • Kim, Hyo-Sook;Kim, Ji-Hyeon
    • Journal of the Korea Fashion and Costume Design Association
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    • v.17 no.3
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    • pp.207-224
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    • 2015
  • Protective clothing for riot policewomen is worn by policewomen to protect their body at suppressing a riot. Plastic guards of Nylon 66 material are attached to the base of E.V.A. Foam material. Protective clothing for riot policewomen consists of a jacket, guards for arms and legs, upper arm braces, and thigh pads. This study was aimed to develop the base pattern of the jacket to protect the torso and to improve the body suitability and the adaptability to movements of protective clothing for riot policewomen. Since current protective clothing worn by riot policewomen is manufactured with the same design of protective clothing for riot policemen, the body suitability and the adaptability to movements are not very satisfactory for policewomen who has different body structure than from riot policemen. Therefore, the purpose of this study is to reflect the body size and characteristics of riot policewomen and develop the base pattern of protective clothing with better body suitability and adaptability to movements. In this respect, amount and place of dots on the jacket were differently designed, made and evaluated by fitting test. The base with the best evaluation was selected as the final experiment clothing to demonstrate its superiority compared with the existing protective clothing.

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