http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
개별검색 DB통합검색이 안되는 DB는 DB아이콘을 클릭하여 이용하실 수 있습니다.
통계정보 및 조사
예술 / 패션
<해외전자자료 이용권한 안내>
- 이용 대상 : RISS의 모든 해외전자자료는 교수, 강사, 대학(원)생, 연구원, 대학직원에 한하여(로그인 필수) 이용 가능
- 구독대학 소속 이용자: RISS 해외전자자료 통합검색 및 등록된 대학IP 대역 내에서 24시간 무료 이용
- 미구독대학 소속 이용자: RISS 해외전자자료 통합검색을 통한 오후 4시~익일 오전 9시 무료 이용
※ 단, EBSCO ASC/BSC(오후 5시~익일 오전 9시 무료 이용)
Metal matrix composites had generated a lot of interest in recent time because of their high specific strength and stiffness in specific properties. It was also highlighted as the material of frontier industry because strength, heat-resistance, corrosion-resistance and wear-resistance were superiored. In this study, the strength properties of AI18B4O33/AC4CH composites were represented mixing the binder of SiO2. It was also fabricated by squeeze casting. AI_18B_4O_33/AC4CH was fabricated at the melt temperature of 760℃, the perform temperature of 700℃ and mold temperature of200℃ under the pressure of 83.4MPa. Consequently, fatigue life was observed roughly in the order of AC4CH) nobiner) SiO_2, independently on crack propagation direction and stress ratio.<br/>
Recently, many components used in machinery industry demand lightness and high strength. The shot-peening method is used in order to improve fatigue life of spring steel(SUP-9) which is used in suspension of automobile. The compressive residual is induced in shot-peening process. This paper investigated the effect of the compressive residual stress on the fracture toughness. The test of Fracture toughness had been conducted at room temperature, high temperature(100℃, 200℃) and low temperature(-60℃, -100℃) from SUP-9 Steel was process by shot-peening. so we survey fractography of SUP-9 Steel by SEM.
Recently, the steel material part used at the automobile and aerospace industries are require to be used lightweight parts. therefore, used material steel have to be a high stress and light, which is an indispensable condition in this field. aluminum alloy is very light and high stress. but many industries are require to more mechanical characteristic. so we need to development research about the aluminum alloy. there are many way for enhance mechanical characteristic of the aluminum alloy. we used the shot peening as way of the enhance mechanical characteristic. The wear test is one of important factors which evaluate the life of the machine. the surface conditions are measured to know the influence wear characteristics by shot peening and influence on material durability wear and friction by shot velocity. test result show the wear characteristics were increased by optimum peening condition. but the wear characteristic were decreased by under peening or overpeening condition. In this study, used a ball on disk type experiment to measure wear less and friction . shot velocity are 40㎧,50㎧ 70㎧ and used specimen are Al7075-T6 and Al6061-T651.
In this study, monolithic MoSi₂, 20 vol.% SiC particles-reinforced MoS₂ matrix, SiC/MoSi<br/> composite and 20 vol.% ZrO₂ panicles-reinforced MoSi₂ matrix, ZrO₂/MoSi₂ composite was fabricated by hot pressed sintering at 1350℃ under 30 ㎫ during 60 min. Vickers hardness and sliding wear resistance of the monolithic MoSi₂, ZrO₂/MoSi₂ and SiC/MoSi₂ composite was investigated at room temperature. Abrasion tester used a pin-on-disk type and a Si3N4 ceramic ball which used as machine structural materials. The test condition apply to load of 8kgf a 7.5rpm for 6 hours and the effect of hardness is also discussed The ZrO₂/MoSi₂ composite has shown the very excellent wear resistance compared with monolithic MoSi₂ and SiC/MoSi composite at room temperature.<br/>
In this study, liquid phase sintered SiC (LPS-SiC) materials were made by hot pressing method. The particle size of nano-SiC powder was 30㎚. Alumina (Al₂O₃), yttria (Y₂O₃) and silica (SiO₂) were used for sintering additives. To investigate effects of SiO₂, ratios of SiO₂ contents were changed by five kinds. Materials have been sintered for 1 hour at 1760℃, 1780℃ and 1800℃ under the pressure of 20㎫. The system of sintering additives which affects a property of sintering as well as the influence depending on compositions of sintering additives were investigated by measurement of density, mechanical properties such as flexural strength, vickers hardness and sliding wear resistance were investigated to make sure of the optimum condition which is about matrix of SiCf/SiC composites. The abrasion test condition apply to load of 20N at 100RPM for 20min. Sintered density, flexural strength of fabricated LPS - SiC increased with increasing the sintering temperature. And in case of LPS-SiC with low SiO₂, sliding wear resistance has very excellent. Monolithic SiC 1800℃ sintering temperatures and 3wt% have excellent wear resistance.
Recently, the steel parts used for automobiles and trains are required to be used under higher stress than ever before in need of the weight down. To achieve this requirement of a high strength steel, it must be necessary to decrease the inclusion contents and surface defects such as decarburization, surface roughness etc. In this study, the results of observation on the arc height, surface roughness, hardness, residual stress and fatigue life of a Al6061-T651 shot peened were obtained. Experimental results show that the increase of arc height is tremendous by shot velocity. Also shows that increase of surface roughness, hardness and compressive residual stress, fatigue life of Al6061- T651 by shot velocity.
In this study, monolithic liquid phase sintered SiC (LPS-SiC) was made by hot pressing method with nano-SiC powder whose a particle size is 30㎚ and less on the average. Alumina (Al₂O₃), yttria (Y₂O₃) and silica (SiO₂) were used for sintering additives. To investigate effects of SiO₂, Al₂O₃/Y₂O₃ composition was fixed and then ratios of SiO₂ were changed as seven kinds. Materials have been sintered for 1 hour at 1760℃, 1780℃ and 1800℃ under the pressure of 20㎫. The system of sintering additives which affects a property of sintering as well as the influence depending on compositions of sintering additives were investigated by measurement of density, mechanical properties such as flexural strength, vickers hardness and sliding wear resistance were investigated to make sure of the optimum condition which is about matrix of SiCf/SiC composites. The abrasion test condition apply to load of 20N at 100RPM for 20min. Sintered density, flexural strength of fabricated LPS - SiC increased with increasing the sintering temperature. And in case of LPS-SiC with low SiO₂, has very excellent wear resistance.
Nowadays, many components used in aerospace and automobile industry were required lightness and high strength. The shot peening process is most often used to improve fatigue properties of metal part. The shot peening method is in used in order to improve the fatigue life of Aluminum alloy which is used in aerospace and automobile industries. The compressive residual stress is induced in this shot peening process. This paper is investigated the effect of the compressive residual stress on the fatigue crack growth characteristics and we found the optimum shot peening condition. Test results show the fatigue characteristics were increased by optimum peening condition. But the fatigue characteristics were decreased by under peening or over peening condition. The fatigue life and fatigue strength of shot peened specimens are higher than those of unpeened specimens. Fatigue crack growth tests on compact tension specimen of width 12.5㎜ were conducted by using sinusoidal waveform and used the Servo hydraulic fatigue testing machine (MTS 810). Compact tension specimens were used and crack growth rate da/dN and stress intensity factor range ΔK were analyzed concerning to the R value of 0.1. Shot peening was performed on velocity of 40㎧, 50㎧, 70㎧ by impeller type shot peening machine, and used compact tension specimen are Al7075-T6 and Al6061-T651.
At present, welding technology is not only emphasized in the development of manufacturing technology but also application is expanding. In these systems, application of SUS as high-temperature material which is used for special purposes is attempted, and improvement of manufacturing technologies bear watching together with increase of using rate. Specifically, Wings with surface of three-dimensional shape usually applied to Fastener with purpose of lightweight. However, due to development of welding technology, methods of existing assembly tend to be replaced by welding, recently. Specifically, if laser welding techniques is applied, it minimizes heat-affected zone than other welding techniques. However, in the case of these special welding, residual stress is raised, and it fatally affects fatigue life. In order to remove residual stress and delay effect of fatigue life, shot-peening is executed; it executes shot-peening and verifies delayed effects of fatigue life. The intention of this study is to obtain the optimal conditions of shot-peening.
Recently, the steel parts used at the aerospace and automobile industries are required to be used light weight parts. Therefor, used material, steel have to be a high stress, which is an indispensable condition in this field. At the consideration of parts design, high hardness of the lightweight parts have an benefit of saving fuel and material. A high stress of metal has a point of difference according to the shape of design, external cyclic load and condition of vibration. A crack generates on the surface of metal or under yield stress by defect of inner metal defect or surface defect and slowly, this crack grow stable growth. Finally, rapidity failure phenomena is happen. Fatigue failure phenomena, which happen in metal, bring on danger in human life and property. therefor, antifatigue failure technology take an important part of current industries Currently, the shot peening is used for removing the defect from the surface of steel and improving the fatigue strength on surface. Therefor, this paper investigated the effect on frcature toughness using shot peening which is improve the resistance of crack growth and crack expansion rate by fatigue that make a compressive residual stress on surface.<br/>