In this study, the various process conditions for high-power DC Magnetron Sputtering (DCMS) on the surface roughness of carbon thin films were investigated. The optimal conditions for Si/C coating were 40min for deposition time, which does not deviate from normal plasma, to obtain the maximum deposition rate, and the conditions for the best surface roughness were – 16volt bias voltage and 400watt DC power with 1.3x10-3torr chamber pressure. Under these optimal conditions, an excellent carbon thin film with a surface roughness of 1.62nm and a thickness of 724nm was obtained. As a result of XPS analysis, it was confirmed that the GLC structure ( bonding) was more dominant than the DLC structure ( bonding) in the thin film structure of the carbon composite layer formed by DC sputtering. Except in infrequent cases of relatively plasma instability, the lower bias voltage and applied power induces smaller surface roughness value due to the cooling effect and particle densification. For the optimal conditions for Graphite/C composite layer coating, a roughness of 36.3 nm and a thickness of 711 nm was obtained under the same conditions of the optimal process conditions for Si/C coating. This layer showed a immensely low roughness value compared to the roughness of bare graphite of 242 nm which verifies that carbon coating using DC sputtering is highly effective in modifying the surface of graphite molds for glass forming.

By developing molds and facilities to horizontally mold the functional part of the dry-cast concrete block, We intend to develop molds and a series of facilities to horizontally mold the functional part of the dry-cast concrete block to increase production per cycle while maintaining existing production methods and major facilities. In order to do so, CAE analysis is first required to develop molds and facilities for horizontally molding the functional part of the drycast concrete block in the horizontal direction. The procedure will be carried out by reviewing the validity of boundary conditions and physical properties, 3D modeling, grid generation, construction of analysis models, model validity, analysis according to frequency changes, and analysis according to physical properties. First, through the comparison of two-point support, three-point support, and two-point and three-point support in the constraint conditions, We would like to compare it with the actual molded product in the horizontal direction. But first of all, it is considered two-point support in the constraint conditions in this paper.

In this paper, to improve the optical quality of aspherical plastic lenses for mobile use, the optimal molding conditions that can minimize the phase difference are derived using injection molding simulation, design of experiments, and machine learning. First, factors affecting the phase difference were derived using the design of the experiment method, and a data set was created using the derived factors, followed by the machine learning process. After predicting the model trained using the generated training data as test data and verifying it with the performance evaluation index, the model with the best predictive performance was the random forest model. Therefore, to derive the optimal molding conditions, random forests were used to predict 10,000 random pieces of data. As a result of applying the derived optimal molding conditions to the injection molding simulation, the phase difference of the lens could be reduced by 8.2%.

To improve the shortcomings and expand the advantages of the single-roll melt drag method, which is a type of continuous strip casting method, the melt drag method with a molding belt is applied to AZ31 magnesium alloy. By attaching the forming belt to the melt drag method, the cooling condition of the thin plate is improved, making it possible to manufacture thin plates even at high roll speed of 100 m/min or more. In addition, it is very effective for continuous production of thin plates to suppress oxidation of the molten metal on the roll contact surface by selecting the protective gas. As a result of investigating the relationship between the contact time between the molten metal and the roll and the thickness of the sheet, it is possible to estimate the thickness of the sheet from the experimental conditions. The relationship between the thin plate thickness and the grain size is one in which the thinner the thin plate is, the faster the cooling rate of the thin plate is, resulting in finer grain size. The contact state between the molten metal and the roll greatly affects the grain size, and the minimum average grain size is 72 μm. The thin plate produced using this experimental equipment can be rolled, and the rolled sample has no large cracks. The tensile test results show a tensile strength of 303 MPa.

In this study, we used a numerical analysis program to study the molding conditions that affect the flow rate at the time of injection, using a spiral mold, which is mainly used for the evaluation of the flow rate of plastic resin. The mold temperature, melt temperature, and flow rate are composed of experimental factors. The three plastic forming factors were divided into five to six levels each. Since then, changes in the flow rate temperature were analyzed as the level of each forming factor increased. Experiments showed that all three forming factors increased the filling length of the spiral mold and the temperature of the flow front by a total of 34.53°C, melt temperatures increased the temperature of the flow front by a total of 34.53°C, the temperature increased by the flow rate was 23.5°C, and the temperature increased by the mold temperature was 1.99°C. It was shown that the melt temperature was the largest, followed by the flow rate and mold temperature. It was also possible to check the effect of plastic forming factors on the speed of the flow front.

Warpage of injection molded product is caused by non-uniform shrinkage and residual stress. A method of removing uneven molding shrinkage and residual stress is to remove the defective factor to Uniform cooling of products. Warpages for part designs have been investigated in this study according to the injection molding conditions for amorphous ABS and crystalline PP by the rapid cooling and heating system. Experimental results showed that the crystalline resin was more warped than amorphous resin, Warpages have been observed in the regions of the part, near gate region and flow direction region.

전분과 구연산 사이의 다중 에스테르화반응에 의한 starch citrate의 저항전분 함량에 대한 반응압출성형조건들의 영향을 조사하였으며, 이들의 페이스팅 점도 특성을 조사하여 산업적 활용도가 높은 starch citrate를 제조할 수 있는 반응조건을 탐색하였다. 반응압출성형에 의한 starch citrate를 제조하기 위해 성형노즐을 제거한 쌍축압출성형기를 사용하여 반응온도, 스크류 회전속도, 반응혼합물의 쌍축압출성형기 통과횟수를 변수로 하였다. 반응온도가 높아지면서, 스크류 회전속도가 느려지면서, 쌍축압출성형기 통과횟수가 증가하면서 starch citrate의 저항전분 함량은 증가하는 경향을 나타내었다. 40% 구연산 농도의 반응혼합물을 150oC와 스크류 회전속도 10 rpm의 쌍축압출성형기를 5회 통과시킬 때 90%의 저항전분을 보유한 starch citrate를 얻을 수 있었다. 또한 40% 구연산 농도의 반응혼합물을 150oC와 스크류 회전속도 50 rpm의 쌍축압출성형기를 5회 통과시킬 때 58%의 저항전분을 보유한 starch citrate를 얻을 수 있었으며, 이는 유의적인 페이스팅 점도를 발달시켜 높은 저항전분 함량에도 불구하고 가공적성이 우수한 starch citrate를 얻을 수 있었다. 또한 starch citrate의 제조 시 전통적으로 사용되는 컨백션 오븐 보다는 쌍축압출성형기를 사용하는 것이 가공적성이 우수한 starch citrate를 제조할 수 있을 것으로 보인다. 따라서 본 연구에서 보고한 50%(s.b) 이상의 저항전분을 보유하면서도 페이스팅 점도 특성을 잃지 않은 starch citrate와 쌍축압출성형기를 활용한 starch citrate 제조기법들은 산업적 활용도 높을 것으로 예상되며 기존의 저항전분 소재들을 대체할 수 있는 잠재력이 높은 저항전분 소재일 것으로 생각된다.

본 연구는 수분함량 22, 25, 28%, 스크루 회전속도 200, 250 rpm, 용융물 온도 110, 120, 130℃의 조건범위로 조절하고 원료 사입량 100 g/min으로 고정하여 압출 성형한 밤과육의 물리적 특성(직경 팽화율, 비길이, 체적밀도), 수분용해지수 및 수분흡착지수, 환원당 함량과 항산화 활성에대해 분석하였다. 밤 압출성형물은 직경 팽화율이 증가할수록 비길이와 체적밀도는 감소하였고, 수분용해지수와 수분흡착지수는 수분함량이 낮아질수록 증가하였다. 압출성형을 통하여 환원당 함량, DPPH 라디칼 소거능, 총 페놀함량 및 플라보노이드 함량은 감소하였으며, 탄닌함량은 압출성형을 통해 2.94±0.10−4.23±0.12 mg/g 범위로 낮아지는 경향을 나타내었다. 결론적으로 압출성형 후 수분용해지수의 증가는 밤 음료의 용해도 개선의 효과를 나타낼 수 있으며, 또한 압출성형공정은 소비자 기호성에 영향을 미치는 탄닌의 쓴맛을 감소시키는 가능성을 제시하였다. 이를 통해 다양한 식품의 중간소재로써 압출성형 밤이 활용 될 수 있다고 판단된다. 밤의 식품중간소재 기초자료로서 응용될 것으로 생각되지만, 압출성형 최적조건을 보다 효과적으로 도출하기 위한 연구가 필요할 것으로 판단된다.

본 연구는 수분함량 22, 25, 28%, 스크루 회전속도 200, 250 rpm, 용융물 온도 110, 120, 130℃의 조건범위로 조절하고 원료 사입량 100 g/min으로 고정하여 압출 성형한 밤과육의 물리적 특성(직경 팽화율, 비길이, 체적밀도), 수분용해지수 및 수분흡착지수, 환원당 함량과 항산화 활성에 대해 분석하였다. 밤 압출성형물은 직경 팽화율이 증가할수록 비길이와 체적밀도는 감소하였고, 수분용해지수와 수분흡착지수는 수분함량이 낮아질수록 증가하였다. 압출성형을 통하여 환원당 함량, DPPH 라디칼 소거능, 총 페놀함량 및 플라보노이드 함량은 감소하였으며, 탄닌함량은 압출성형을 통해 2.94±0.10−4.23±0.12 mg/g 범위로 낮아지는 경향을 나타내었다. 결론적으로 압출성형 후 수분용해지수의 증가는 밤 음료의 용해도 개선의 효과를 나타낼 수 있으며, 또한 압출성형공정은 소비자 기호성에 영향을 미치는 탄닌의 쓴맛을 감소시키는 가능성을 제시하였다. 이를 통해 다양한 식품의 중간소재로써 압출성형 밤이 활용 될 수 있다고 판단된다. 밤의 식품중간소재 기초자료로서 응용될 것으로 생각되지만, 압출성형 최적조건을 보다 효과적으로 도출하기 위한 연구가 필요할 것으로 판단된다.

옥수수 섬유질을 수분함량 20과 30%, 스크루 회전속도 150과 200 rpm으로 조절하고 배럴온도 160oC, 원료 사입량을 120 g/min으로 고정하여 압출성형하였 때, 압출성형 조건이 옥수수 섬유질의 화학적 특성(일반성분, 환원당 함량, 항산화 활성, 효소 반응성), 비기계적 에너지 투입량, 물리적 특성(팽화율, WSI, WAI)에 미치는 영향을 연구하였다. 압출성형에 의하여 환원당과 전분, 항산화 활성, 효소반응성, WSI가 증가하였다. 특히 수분함량 20%에서 증가폭이 더 컸다. 효소반응성은 Viscozyme L에 대한 반응성이 더 컸으며, 특히 수분함량 20%, 스크루 회전속도 200 rpm에서 효소반응성이 가장 높았다. 수분함량이 20에서 30%로 증가할 때 비기계적 에너지 투입량은 감소하였으며, 직경 팽화율과 WSI도 감소하였으나, 비길이 및 WAI는 증가하였다. 본 연구에서 수분함량이 압출성형 옥수수 섬유질의 중요한 변수로 작용하는 것을 알 수 있었다.

In order to improve the remanence of (Nd, Dy)-Fe-B sintered magnets, we investigated the influence of compaction conditions such as packing density, applied field and green density on the magnetic properties. While the remanence decreased with increasing the packing density and green density, it increased with the increase of the applied field. In addition, XRD analysis revealed that the remanence was enhanced as the degree of powder alignment was improved. The green density was more influential on the remanence than the packing density and applied field.

High speed steels (HSS) were used as cutting tools and wear parts, because of high strength, wear resistance, and hardness together with an appreciable toughness and fatigue resistance. Conventional manufacturing process for production of components with HSS was used by casting. The powder metallurgy techniques were currently developed due to second phase segregation of conventional process. The powder injection molding method (PIM) was received attention owing to shape without additional processes. The experimental specimens were manufactured with T42 HSS powders (59 vol%) and polymer (41 vol%). The metal powders were prealloyed water-atomised T42 HSS. The green parts were solvent debinded in normal n-Hexane at for 24 hours and thermal debinded at mixed gas atmosphere for 14 hours. Specimens were sintered in , gas atmosphere and vacuum condition between 1200 and . In result, polymer degradation temperatures about optimum conditions were found at and . After sintering at gas atmosphere, maximum hardness of 310Hv was observed at . Fine and well dispersed carbide were observed at this condition. But relative density was under 90%. When sintering at gas atmosphere, relative density was observed to 94.5% at . However, the low hardness was obtained due to decarbonization by hydrogen. In case of sintering at the vacuum of torr at temperature of , full density and 550Hv hardness were obtained without precipitation of MC and in grain boundary.

Defining the relationship between the quality of injection molded parts and the process condition is very complicate because of lots of factor are involved and each factor has a non-linearity. With the development of CAE(Computer Aided Engineering) technology, the estimation of volumetric shrinkage of injection mold parts is possible by computer simulation even though restricted application. In this research, the Taguchi method and Neural Network applied for finding optimal processing condition. The percent of volumetric shrinkage compared on each case and show neural network can be successfully applied.

The present study is concerned with the effect of PM process variables on the microstructure by using atomized superalloy powders. It is suggested that the inhomogeneity of composition is strongly dependent on the process variables. The contents of segregation elements of plasma rotating electrode process (PREP) powders are larger than those of Ar atomization (AA) powders. As HIP treatment temperature in-increases, the secondary phases on the prior particle boundaries (PPB) have continuous,uniform distribution and high density, but the amount of PPB decreases suddenly at 1150C. Segregated phases on the PPB are identified to be MC type carbide. Brittle MC type carbides on the PPB provide fracture initiation sites and preferred fracture path, thereby leading to intergranular type brittle fracture.