http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Mg-xSn(x = 1, 3, 5, 7, 9 wt.%) 합금의 미세조직 및 부식특성
강용묵 ( Yong Muk Kang ),김상현 ( Sang Hyun Kim ),조수미 ( Su Mi Jo ),박경철 ( Kyung Chul Park ),김병호 ( Byeong Ho Kim ),박익민 ( Ik Min Park ),박용호 ( Yong Ho Park ) 한국주조공학회 2011 한국주조공학회지 Vol.31 No.6
In the present work, the corrosion properties of Mg-xSn (x = 1, 3, 5, 7 and 9 wt.%) alloys have been investigated. Potentiodynamic polarization and immersion tests were carried out in 3.5% NaCl solution of pH 7.2 at room temperature to measure the corrosion properties of Mg-xSn (x = 1, 3, 5, 7 and 9 wt.%) alloys. With increase of the Sn contents, the volume fraction of the Mg2Sn phase was increased. The corrosion rate of Mg-xSn alloys was increased up to 7 wt.%Sn and decreased above 9 wt.%Sn. Initiation of galvanic site during immersion mainly occurred at Mg/Mg2Sn interface and propagation went into α-Mg. For this reason, corrosion properties of Mg-xSn (added from 1 wt.%Sn to 7 wt.%Sn alloys) alloys are decreased because the galvanic site was increased with increasing Sn addition. In Mg-9wt.%Sn alloy, however, the corrosion site were changed from Mg/Mg2Sn interface to α-Mg/M2Sng interface in lamellar structure. Preferentially corrosion of α-Mg/M2Sn interface in lamellar structure impeded corrosion propagation went into α-Mg.
AZ31-xCa (x=0, 0.7, 2.0 wt.%) 압출재의 압축변형시 파괴거동
강나은 ( Na Eun Kang ),임창동 ( Chang Dong Yim ),유봉선 ( Bong Sun You ),박익민 ( Ik Min Park ) 대한금속·재료학회 2010 대한금속·재료학회지 Vol.48 No.1
The plastic deformation behavior of magnesium alloy is affected simultaneously by deformation temperature and strain rate under warm and/or hot working conditions. The soundness of deformation of AZ31-xCa (x=0. 0.7, 2.0 wt.%) extrudes during compression was strongly affected by processing variables including deformation temperature, strain rate. compression-loading direction, which was related to the activation of available deformation systems. The deformation behavior of AZ31-xCa extrudes was also affected by Ca content, which was related to the change of the sort and fraction of second phase. The complex effects of deformation temperature and strain rate on the deformation behavior of AZ31-xCa extrudes during compression under various conditions could be successfully described by Zener-Hollomon parameter.
Al 박육 다이캐스팅 주물에서 기포결함에 미치는 주물두께, 사출속도의 영향
강호정 ( Ho Jeong Kang ),박진영 ( Jin Young Park ),김억수 ( Eok Soo Kim ),조경목 ( Kyung Mox Cho ),박익민 ( Ik Min Park ) 한국주조공학회 2015 한국주조공학회지 Vol.35 No.4
The Al die casting process has been widely used in the manufacturing of automotive parts when the process requires near-net shape casting and a high productive rate. However, porosity arises in the casting process, and this hampers the wider use of this method for the creation of high-durability automotive components. The porosity can be controlled by the shot condition, but, it is critical to set the shot condition in the sleeve, and it remains difficult to optimize the shot condition to avoid air entrapment efficiently. In this study, the 4.5 mm, 2.0 mm plate die castings were fabricated under various shot conditions, such as plunger velocities of 0.7 m/s ~ 3.0 m/s and fast shot set points of the cavity of -25%, 0%, 25%, and 50%. The mold filling behavior of Al melts in the cavity was analyzed by a numerical method. Also, according to the shot conditions, the results of numerical analyses were compared to those of die-casting experiments. The porosity levels of the plate castings were analyzed by X-ray CT images and by density and microstructural analyses. The effects of the porosity on the mechanical properties were analyzed by tensile tests and hardness tests. The simulation results are in good general agreements with the die-casting experimental results. When plunger velocity and fast shot set point are 1.0 m/s and cavity 25% position, castings had optimum condition for good mechanical properties and a low level of porosity.
Mg-4Al-2Sn 합금의 고온 기계적 특성에 미치는 Pd첨가의 영향
임시온,강병수,조대현,박익민,Yim, Si-On,Kang, Byoung-Soo,Cho, Dae-Hyun,Park, Ik-Min 한국주조공학회 2017 한국주조공학회지 Vol.37 No.4
This study investigated the effect of Pd on the microstructure, tensile and creep properties of Mg-4Al-2Sn (AT42) alloy at a high temperature for transportation-related industrial applications. AT42-xPd (x = 0, 1 and 2 wt. %) alloys were prepared using a permanent mould casting method. The microstructures of the as-cast alloys were characterized by the presence of the intermetallic phases $Mg_{17}Al_{12}$, $Mg_2Sn$ and $Al_4Pd$. The addition of Pd was found to improve the tensile properties of AT42 at room and at elevated temperatures, and to increase the creep resistance at elevated temperatures. A small amount of Pd could markedly improve the tensile properties of AT42 by means of grain-refinement and the dispersion of secondary phase strengthening. Moreover, the thermally stable phase $Al_4Pd$ effectively improves the creep resistance of AT42 due to the strengthened grain boundaries and the suppressed formation of $Mg_{17}Al_{12}$.
압력용기 고온 고압부의 피로손상 예측을 위한 SH 초음파 평가 기법 개발
강용호(Yong Ho Kang),정용근(Yong Keun Chung),박종진(Jong Jin Park),박익민(Ik Min Park) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.4
Ultrasonic method using SH(shear horizontal) wave has been developed to determine the surface<br/> damage in fatigued material. Fatigue damages based on propagation energy were analyzed by multiregression<br/> analysis and phase measurement in interrupted fatigue test specimen including CrMoV<br/> and 12Cr alloy steel. From the test results, as the fatigue damage increased the propagation time of<br/> the launched waves increased and amplitude of wavelet decreased. Also, analysis for the waveform<br/> modulation showed a reliable estimation, with confidence limit of 97% for 12Cr steel and 95% for<br/> CrMoV steel, respectively. Therefore, It is thought that SH ultrasonic wave technique can be applied<br/> to determine fatigue damage of in-service component nondestructively.
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)
용탕가압침투법에 의한 알루미늄 보레이트 강화 Mg-3Al-2Ag-1Zn 금속복합재료의 물성
강호준,배건희,박용하,한상호,박용호,조경목,박익민,Kang Hojune,Bae Gunhee,Park Yongha,Han Sangho,Park Yongho,Cho Kyungmox,Park Ikmin 한국재료학회 2005 한국재료학회지 Vol.15 No.12
In this study, aluminum borate whisker reinforced Mg-3Al-2Ag-1Zn matrix composites were fabricated by the squeeze infiltration technique. The purpose is to develop materials for elevated temperature applications. Microstructure observation revealed successful fabrication of the metal matrix composites, namely no cast defects such as porosity and matrix/reinforcement interface delamination etc. High temperature hardness and creep rupture properties were improved significantly with addition of Ag to the Al borate whisker reinforced Mg alloy composite. $Mg_3Ag$ phase formed during aging heat treatment could improve creep properties of the Mg matrix composites.