http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Boron 확산침투법에 의한 STD61강종의 표면개질처리에 관한 연구
이상로,남기식,차병묵,윤재홍,변응선 國立 昌原大學校 産業技術硏究所 1995 産技硏論文集 Vol.9 No.-
STD 61 steel was boronized in boronizing paste mainly consisted of B₄C, Na₂B₄O7 at various temperature and times. The microhardness and the thickness of boride layers were measured and the distributions of B, Si, Cr, V on the cross section of specimens were observed by EPMA line analysis. Microscopic examination and the results of EPMA showed that the boride layer consisted of two layer and outer layer was FeB, inner was Fe₂B. The mictohardness of these boride layers were about Hv 1800~2300. Thickness of the boride layer was increased with an increase of square root of time for treatment at constant temperature. The activation energy for diffusion of B in the specimen obtained from the slope of Arrhenius plots was 260kJ/mol. α layer of Si rich was formed at the space between boride layer and matrix. Element such as Cr were concentrated as the Cr23(B,C)6 composition beneath the boride layer.
캐비테이션-에로젼 특성에 미치는 HVOF 용사조건의 영향
변응선,유인준,이규환,박율민 한국표면공학회 2009 한국표면공학회 학술발표회 초록집 Vol.2009 No.10
캐비테이션-에로젼은 침식부식과 유사한 형태의 침식에 의한 손상이다. 즉, 고속의 애체흐름에 노출된 금속 표면을 따라 압력변화에 의해서 생성된 기포들이 파괴되는 것과 관련하여 일어나는 표면손상의 한 형태이다 . 본 연구에서는 캐비테이션-에로젼 손상을 억제하기 위하여 WC 서멧을 HVOF 용사하였으며, 캐비테이션-에로젼 특성에 미치는 용사조건의 영향에 중점을 비교분석하였다.
질소이온 주입이 생체적합성 티타늄 임플란트의 마모특성에 미치는 영향
변응선,김동수,이구현,정용수,Byeon, Eung-Seon,Kim, Dong-Su,Lee, Gu-Hyeon,Jeong, Yong-Su 한국기계연구원 2000 硏究論文集 Vol.30 No.-
Since the concept of osseointegration was introduced, titanium and titanium-based alloy materials have been increasingly used for bone-anchored metal in oralmaxillofacial and orthopedic reconstruction. Successful osseointegration has been attributed to biocompatibility and surface condition of metal implant among other factors. Although titanium and titanium alloys have an excellent over the metal ion release and biocompatibility, considerable controversy has developed over the metal ion and wear debris in vivo and vitro. In this study, nitrogen ion implantation technique was used to improve the corrosion resistance and wear property of titanium materials, ultimately to enhance the tissue reaction to titanium implants As ion implantation energy was increased, projected range of nitrogen ion the Ti substrate was gradually increased. Under condition of constant ion energy. atomic concentration of nitrogen was also increased with ion doses. The friction in Hank's solution was increased with ion doses. The friction coefficient of ion implanted specimens in HanK's solution was increased from 0.39, 0.47 to 0.52, 0.65 respectively under high energy and ion dose conditions. As increasing ion energies and ion dose, amount of wear was reduced.
가공열처리한 Al-Zn-Mg합금의 피로균열 성장거동에 미치는 하중비의 영향
변응선,김송희 ( E . S . Byun,S . H . Kim ) 한국열처리공학회 1989 熱處理工學會誌 Vol.2 No.4
Fundmental fatigue crack propagation tests with C-T type specimens were conducted at various load ratios (R) such as 0.1, 0.3 and 0.5 in T6 and Thermomechanically treated (TMT) conditions of 7039 Al alloy. Better mechanical properties from monotonic test as well as fatigue crack propagation were obtained by TMT process owing to uniform distribution of fine microstructures and non-existence of precipitation free zone (PFZ). Through the measurement of Kop and ΔK at various R the concept of effective stress intensity factor range ratio, U was reviewed to asses the load ratio effect on fatigue crack propagation. A relationship between U and variables such as ΔK and R was obtained empirically. This may enable us to predict ΔK_(eff) that is of critical importance for prediction of fatigue crack propagation rate.