• 한국주조공학회지
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• 제33권4호
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• pp.171-180
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• 2013

The effects of alloying elements on the solidification characteristics, microstructure, thermal conductivity, and tensile strength of Al-Zn-Mg-Fe alloys were investigated for the development of high strength and high thermal conductivity aluminium alloy for die casting. The amounts of Zn and Mg in Al-Zn-Mg-Fe alloys had little effect on the liquidus/solidus temperature, the latent heat for solidification, the energy release for solidification and the fluidity of Al-Zn-Mg-Fe alloys. Thermo-physical modelling of Al-Zn-Mg-Fe alloys by the JMatPro program showed $MgZn_2$, AlCuMgZn and $Al_3Fe$ phases in the microstructure of the alloys. Increased amounts of Mg in Al-Zn-Mg-Fe alloys resulted in phase transformation, such as $MgZn_2{\Rightarrow}MgZn_2+AlCuMgZn{\Rightarrow}AlCuMgZn$ in the microstructure of the alloys. Increased amounts of Zn and Mg in Al-Zn-Mg-Fe alloys resulted in a gradual reduction of the thermal conductivity of the alloys. Increased amounts of Zn and Mg in Al-Zn-Mg-Fe alloys had little effect on the tensile strength of the alloys.

• Journal of Advanced Marine Engineering and Technology
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• 제9권3호
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• pp.240-249
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• 1985

This paper presents the results of the galvanic anode's characteristicsin the Al-Zn-In-Mg and Al-Zn-In-Mg system anodes used aluminium ingot of low purity, 99.5% grade. The results of thses performance tests are as follows: 1) Zn, In and Mg are an available elements to improve the performance of Aluminium alloy anodes. 2) When the range of zinc content in the Al-Zn-In-Mg system anode is 2-5% the more zinc content, the more improve the anode performance. 3) Al-Zn-In-Mg system anode requires a long term over 50 days for the performance test. 4) The composition of Al-Zn-In-Mg system anode which shows the most excellent performance is Al-(2-3%) Zn-(0.02%) In-(1.0%) Mg. 5) When the Al-Zn-In-Mg system anode is annealed for an hour in 500 to 550 .deg. C, the anode performance is improved. 6) The lower average potential and the better corrosion pattern in the Al-Zn-Mg, Al-Zn-In and Al-Zn-In-Mg system anodes, the more current efficiency is improved.

• 한국주조공학회지
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• 제43권6호
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• pp.286-293
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• 2023

본 연구에서는 고강도 Al-Mg-Zn계 알루미늄 합금 연속주조 빌렛의 균질화처리 과정 중 미세조직 전개과정을 다양한 장비(OM, SEM, EDS, DSC)로 분석 및 고찰하였다. 우선, 연속주조된 알루미늄 합금 빌렛 내 입계 및 입내에는 AlMgZn, AlMgFe 및 AlMgZnSi상 등 많은 양이 불균일하게 존재하며, 이들 상은 균질화처리 과정 중 입계 및 기지로 용해된다. 합금설계 프로그램 및 동력학 방정식을 활용한 결정립 내 주요 합금원소인 Mg 및 Zn의 확산거동을 분석한 결과, JMatPro 내 균질화처리 모드에서 대상합금 내 Mg이 Zn 대비 기지 내로 빠르게 용해되나, 동력학 방정식의 경우에도 유사한 경향성이 나타난다. 확산속도에 대한 의미로 실제로 Zn 대비 상대적으로 Mg이 많은 양을 함유하고 있어 기지로 확산과 동시에 고용되었음을 확인할 수 있었다.

• 한국주조공학회지
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• 제30권4호
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• pp.137-141
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• 2010

The effects of Zn amounts on the castability and tensile properties of Al-Zn-Mg-Cu alloys were investigated for development of high strength die casting aluminium alloys. Al-Zn-Mg-Cu alloys with 3.5% Zn showed high cast cracking tendency and poor mold filling behaviour. Al-Zn-Mg-Cu alloys with 5wt% Zn and 7wt% Zn had the tensile strengths of 300~400MPa and the elongations of 2~18%. The effect of Zn on the tensile strength of Al-Zn-Mg-Cu alloys was insignificant, but Al-Zn-Mg-Cu alloy with high Zn amount had lower elongation.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 춘계학술발표회 논문집
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• pp.280-280
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• 2012

Mg의 첨가한 Zn-Mg-Al 합금도금강판에 형성된 $Zn-MgZn_2$ 공정조직의 부식거동을 이해하고자 진공 고주파 용해로 $MgZn_2$ 제작한 후 Zn와 galvanic coupling하여 $MgZn_2$합금과 Zn간의 galvanic corrosion 거동을 알아보았다. $MgZn_2-Zn$ galvanic coupling의 SVET 결과에서 $MgZn_2$가 anode, Zn가 cathode가 됨을 확인되었다. $MgZn_2$의 Zn와의 galvanic corrosion 평가에서 galvanic current는 Zn 보다 낮은 potential에서 anodic current density를 나타내었으며, galvanic potential은 $MgZn_2$전위로부터 두 합금의 혼합전위를 향해 증가함을 알 수 있었다. Zn-Mg-Al 합금도금강판의 염수분무 평가에서도 초기 $Zn-MgZn_2$ 공정조직에서 $MgZn_2$가 용출되는 것이 관찰되었다.

• 한국주조공학회지
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• 제33권3호
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• pp.113-121
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• 2013

The effects of Zn and Mg amounts on the solidification characteristics, microstructure, thermal conductivity and tensile strength of Al-Zn-Mg-Fe alloys were investigated for the development of high thermal conductivity aluminium alloys for die casting. Zn and Mg amounts in Al-Zn-Mg-Fe alloys had a little effect on the liquidus / solidus temperature, the latent heat for solidification and the fluidity of Al-Zn-Mg-Fe alloys. Thermo-physical modelling of Al-Zn-Mg-Fe alloys by JMatPro program showed $MgZn_2$, AlCuMgZn and Al3Fe phases on microstructure of their alloys. Increase of Zn and Mg amounts in Al-Zn-Mg-Fe alloys resulted in gradual reduction of the thermal conductivity of their alloys. Increase of Mg amounts in Al-2%Zn-Mg-Fe alloys had little effect on the tensile strength of their alloys, but increase of Mg amounts in Al-4%Zn-Mg-Fe alloys resulted in steep increase of the tensile strength of their alloys.

• 열처리공학회지
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• 제20권5호
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• pp.243-249
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• 2007

The age hardening behavior and mechanical properties of an extruded Al-Zn-Mg-(Cu)-0.1 wt.%Sc alloy were investigated with the Sc addition and ageing temperature. The results showed that the $Al_3Sc$ compounds were formed by Sc addition and distributed preferentially along the extrusion direction. The age hardening of Al-Zn-Mg-Cu-0.1 wt.%Sc alloy which was treated by T6 process was more significant than that of Al-Zn-Mg-0.1 wt.%Sc alloy. The tensile property of Al-Zn-Mg-Cu+0.1 wt.%Sc alloy was also higher than that of Al-Zn-Mg-0.1 wt.%Sc alloy, which is 691 MPa and 584 MPa in strength and 9% and 11% in elongation, respectively.

• 열처리공학회지
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• 제36권4호
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• pp.198-205
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• 2023

We investigated the effects of Al and Mg on the microstructure and hardness of the coating layer of galvanized steel sheets, by thermodynamic calculations, X-ray diffraction, scanning electron microscopy, and Vickers hardness tests of Zn-0.2Al, Zn-6Al-2Mg, and Zn-10Al-5Mg coating layers. Regardless of the alloy composition of the galvanizing bath, a Fe-Al layer was observed between the coating layer and steel sheet. The Zn-0.2Al coating layer consists of major h.c.p. Zn phase and minor f.c.c. Al phase. The fraction of f.c.c. Al phase (containing a significant amount of Zn) of the coating layer increases with increasing the chemical composition of Al of the galvanizing bath. The h.c.p. MgZn₂ phase was formed in the Al/Mg-containing Zn-6Al-2Mg and Zn-10Al-5Mg coating layers, forming Zn-Al-MgZn₂ eutectic microstructure. The primary MgZn₂ phase was additionally formed in the Zn-10Al-5Mg coating layers containing high concentrations of Al and Mg. The Vickers hardness values of Zn-0.2Al, Zn-6Al-2Mg, and Zn-10Al-5Mg coating layers were 59.1 ± 1.2 HV, 161.2 ± 5.7 HV, and 215.5 ± 40.3 HV, respectively. The addition of Al and Mg increased the hardness of the coating layer by increasing the fraction of the Al phase (containing Zn) and MgZn₂ intermetallic compound, which were harder than the Zn phase.

• 한국주조공학회지
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• 제24권6호
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• pp.340-346
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• 2004

초정 $Mg_2Si$와 미세한 $MgZn_2$ 석출상을 갖는 고강도 내마모 Al합금을 개발하기 이하여 Al-l2wt%Mg-5.5wt%Zn합금에 0-5wt%까지 Si을 첨가 시켰으며, 미세조직 및 기계적 성질에 미치는 영향을 조사하였다. Si의 함량이 증가함에 따라 형성되는 $Mg_2Si$상의 양이 증가하였으며, 동시에 고강선 온도가 점차적으로 증가함에 따라 효과적인 열처리가 가능해지는 것을 관찰할 수 있었다. 5wt%Si이 첨가된 합금의 경우 적절한 열처리를 통해 미세한 $MgZn_2$ 석출상이 기지에 균일하게 분포한 미세조직을 얻을 수 있었고 이를 통해 인장강도를 현저하게 증가시킬 수 있었다. 또한 Si이 첨가된 Al-Mg-Zn합금은 유동도 및 열간 균열저항성과 같은 주조성면에서도 다른 고강도 Al합금에 비하여 월등히 우수한 것으로 나타났다.

• Corrosion Science and Technology
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• 제23권4호
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• pp.283-288
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• 2024

Hot-dip Zn-Mg-Al coatings have a complex microstructure consisting of Zn, Al, and MgZn₂ phases. Its crystal structure depends on alloy content and cooling rates. Microstructure and corrosion resistance of these coatings might be affected by heat treatment. To investigate effect of heat treatment on microstructure and corrosion resistance of Zn-Mg-Al coatings, Zn-1.5%Mg-1.5%Al coated steel was heated up to 550 ℃ at a heating rate of 80 ℃/s and cooled down to room temperature. At above 500 ℃, the ternary phase of Zn-MgZn₂-Al was melted down. Only Zn and MgZn₂ phases remained in the coating. Heat- and non-heat-treated specimens showed similar corrosion resistance in Salt Spray Test (SST). When a Zn-3.0%Mg-2.5%Al coated steel was subjected to heat treatment at 100 ℃ or 300 ℃ for 200 h and compared with GA and GI coated steels, the microstructure of coatings was not significantly changed at 100 ℃. However, at 300 ℃, most Al in the coating reacted with Fe in the substrate, forming a Fe-Al compound layer in the lower part of the coating. MgZn₂ was preferentially formed in the upper part of the coating. As a result of SST, Zn-Mg-Al coated steels showed excellent corrosion resistance, better than GA and GI.