http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
생체 분해성 임플란트용 Mg-Zn-Ca합금의 기계적 및 부식특성에 미치는 Sr 첨가의 영향
공보관 ( Bo Kwan Kong ),조대현 ( Dae Hyun Cho ),윤필환 ( Pil Hwan Yun ),이정훈 ( Jeong Hun Lee ),박진영 ( Jin Young Park ),박익민 ( Ik Min Park ) 한국주조공학회 2015 한국주조공학회지 Vol.35 No.6
The effect of Sr addition on mechanical and bio-corrosion properties of as-cast Mg-3wt.%Zn-0.5wt.%Ca-xwt.%Sr (x = 0.3, 0.6, 0.9) alloys were examined for application as biodegradable implant material. The microstructure, mechanical properties and corrosion resistance of the as-cast Mg-Zn-Ca-Sr alloys were characterized by using optical microscopy, scanning electron microscopy, tensile testing and electrochemical measurement in Hank``s solution. The as-cast alloys contained α-Mg and eutectic Ca2Mg6Zn3 phases, while the alloys contained α-Mg, Ca2Mg6Zn3 and Mg-Zn-Ca-Sr intermetallic compound when the Sr addition was more than 0.3 wt.%. The yield strength, ultimate tensile strength and elongation increased with the increasing of Sr content up to 0.6 wt.% but decreased in the 0.9 wt.% Sr-added alloy, whereas the corrosion resistance of 0.3 wt.% Sr-added alloy was superior to other alloys. It was thought that profuse Mg-Zn-Ca-Sr intermetallic compound deteriorated both the mechanical properties and corrosion resistance of the as-cast alloy.
ADC12 박육 다이캐스팅 주물 내의 기포결함에 미치는 플런저 속도와 고속전환위치의 영향
강호정 ( Ho Jeong Kang ),박진영 ( Jin Young Park ),김억수 ( Eok Soo Kim ),윤필환 ( Pil Hwan Yun ),박익민 ( Ik Min Park ) 대한금속재료학회(구 대한금속학회) 2016 대한금속·재료학회지 Vol.54 No.2
A die casting process has been widely used in the manufacturing of automotive parts which require near-net shape casting and high productive rates. However, high-pressure die castings usually contain regions of gas porosity due mainly to the entrapment of air or gas in the die during the high-speed injection of molten metal into the die cavity. Gas porosity in castings has hampered the wider use of this method in the creation of high-durability automotive components. However, to establish a shot condition in the shot sleeve during the die casting process is critical, and difficulty remains when attempting to optimize the shot condition to avoid air entrapment effectively. In this study, ADC12 plate die castings were fabricated under various shot conditions, in which different plunger velocities and fast shot set points. In addition, according to the shot conditions, die casting experimental results were compared with an experiment involving a water model and with the results of a numerical analysis. The porosity of the castings was analyzed using CT and using density and microstructural analyses, and the effect of the porosity on the mechanical properties was analyzed using hardness and tensile testing. When the plunger velocity was 1.0 m/s and the fast shot set point is cavity 0, 25% position, the results with the castings were optimal, with good mechanical properties and few areas of porosity. In addition, the simulation results were mostly in agreement with die-casting experimental results.(Received March 18, 2015)