• Journal of the Korean Society for Heat Treatment
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• v.32 no.2
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• pp.57-60
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• 2019

The impact of two-step treatment on the mechanical properties of the 6061 Al alloy was investigated by testing the hardness and electrical conductance values. After two-step aging treatment, the hardness and electrical conductivity of the alloy was increased, and if the first aging treatment temperature was lower than the secondary aging treatment temperature, both the hardness and the electrical conductivity were not increased. The higher the temperature of the first aging treatment, the higher the hardness. The temperature of the first aging treatment is $175^{\circ}C$, $150^{\circ}C$, $120^{\circ}C$, and the second is $175^{\circ}C$ and $120^{\circ}C$.

• Journal of Welding and Joining
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• v.34 no.4
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• pp.34-39
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• 2016

Recently, aluminum alloy has used various industry, such as automobile, shipbuilding and aircraft because of characteristics of low density and high corrosion resistance. Al 6061-T6 is heat treatment materials so it has high strength and mostly used for assembly by mechanical fastening such as a bolting and riveting. In GMA (Gas Metal Arc) welding of alloy, some defects which are hot cracking, porosity, low-mechanical properties and large heat affected zone is generated, because of high heat conductivity. It reduces mechanical properties. In this study, the major factor effected on properties are analyzed after welding in Al 6061-T6 in GMAW, then optimize heat treatment conditions. Plate of Al 6061-T6 with a thickness of 12 mm is welded in V groove and applied welding method is butt joint. Mechanical properties and microstructure are analyzed according to heat treatment condition. Tensile strength, microstructure and Hardness are evaluated. Result of research appears that Al 6061-T6 applied heat treatment show outstanding mechanical properties.

• Journal of Welding and Joining
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• v.20 no.3
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• pp.105-108
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• 2002

Al-alloy is utilized widely as a light-weight material to an automobile, a vessel and many kind of equipment, due to the light-weight and its characteristics that is a good tensile strength, elongation and tenacity for bearing heavy load and weight. Al-alloy has the good property of hot working, cold working and corrosion-resistant. But the exiting fusion welding by using Al has some economical and technical problems, but on the other hand, Friction Stir Welding (FSW) that is new joining method can settle the disadvantages that occur to the fusion welding and Is being applied and extended into the various industry fields. On this study, To analyze accurately the mechanical properties of joining area by FSW in Al 6061 alloy by using finite analysis program with finite element method. The size of HAZ and the thermal distribution is simulated and the mechanical properties around the FSW joining area to the Al-alloy 6061 is examined.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2001.11a
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• pp.20-20
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• 2001

• Proceedings of the KWS Conference
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• 2003.11a
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• pp.259-261
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• 2003

• Proceedings of the KWS Conference
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• 2003.05a
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• pp.179-181
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• 2003

• Corrosion Science and Technology
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• v.18 no.6
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• pp.292-299
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• 2019

The hull material of a high-speed ship may cause erosion damage from fluid impact. When physical erosion and electrochemical corrosion combine, erosion corrosion damage occurs. The aluminum ship is vulnerable to erosion corrosion because it can be operated at high speed. Thus, in this study, Al5052-O and Al6061-T6 aluminum alloys for the marine environment were selected as experimental materials. The erosion corrosion resistance of Al5052-O and Al6061-T6 aluminum alloys in seawater was investigated by an erosion test and potentiodynamic polarization test at the various flow rate (0 m/s, 5 m/s, 10 m/s, 15 m/s, 20 m/s). Erosion corrosion characteristics were evaluated by surface analysis, 3D analysis, SEM analysis, and the Tafel extrapolation method. The results of surface damage analysis after the erosion test showed that Al6061-T6 presented better erosion resistance than Al5052-O. The results of the potentiodynamic polarization test at the various flow rate, corrosion current density by Tafel extrapolation presented lower values of Al6061-T6 than Al5052-O. Al5052-O showed more surface damage than Al6061-T6 at all flow rates. Consequently, Al6061-T6 presented better erosion corrosion resistance than Al5052-O. The results of this study are valuable data for selecting hull material for an aluminum alloy vessel.

• Journal of Korea Foundry Society
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• v.28 no.4
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• pp.179-183
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• 2008

Mechanical properties of the spray-cast Al 6061 alloy with variation of Mg/Si addition were investigated. After spray-cast, hot extrusion was performed at $460^{\circ}C$ then followed ageing treatment to the T6 condition. SEM, EDX, and XRD were used to characterize a ${\beta}(Mg_{2}Si)$ precipitate. The amount of ${\beta}$ precipitate was calculated from the XRD measurements. Hardness, ultimate tensile strength and elongation were tested then compared with those of the Al 6061 alloys made by ingot metallurgy (I/M) and powder metallurgy (P/M). The ultimate tensile strength and elongation of the spray-cast Al 6061 alloy were 318MPa and 16.5%, respectively. These properties were improved in the 2.2 wt%Mg and 1.3wt%Si addition up to 349MPa of UTS and 12.5% of elongation, mainly due to increased amount of a fine supersaturated ${\beta}(Mg_{2}Si)$ precipitate.

• Journal of the Korean institute of surface engineering
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• v.41 no.6
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• pp.341-350
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• 2008

In friction stir welding for 6061-T6 with various traveling speed and rotation speed conditions, the best mechanical characteristics presented in traveling speed of 507 mm/min and rotation speed of 1100RPM. The maximum tensile strength and yield strength increased with the increasing of traveling speed. The result of the electrochemical characteristic evaluation in friction stir welding at optimum conditions for 6061-T6 Al alloy presented a good characteristics compare to base metal.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.222-229
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• 2003

The purpose of this study is to evaluate the mechanical properties of 6061 Al foams, which were fabricated by P/M and multi-step induction heating method, and to build the database, which is needed for computer aided modeling or foam components design. Aluminium foams, consisting of solid aluminium and large quantities of porosities, is widely used in automotive, aerospace, naval as well as functional applications because of its high stiffness at very low density, high impact energy absorption, heat and fire resistance, and greater thermal stability than any organic material. In this study, 6061 Al foams were fabricated for variation of fraction of porosities (%) according to porosities (%)-final heating temperature ( $T_{a3}$) curves. Mechanical properties such as compressive strength, energy absorption capacity, and efficiency were investigated to evaluate the feasibility of foams as crash energy absorbing components. Moreover, effect of the surface skin thickness on plateau stress and strain sensitivity of the 6061 Al foams with low porosities (%) were studied.d.