• Title/Summary/Keyword: 6061Al alloy

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Microstructural and Mechanical Characteristics of the ECAPed P/M 6061 Al Alloy (ECAP가공한 P/M 6061 Al 합금의 미세조직과 기계적 성질)

  • 장시영
    • Journal of Powder Materials
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    • v.9 no.1
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    • pp.43-49
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    • 2002
  • Microstructural and mechanical characteristics of P/M 6061 Al alloy subjected to equal channel angular pressing (ECAP) were investigated. The P/M 6061 Al alloy had an intial grain size of approximately $20\mutextrm{m}$. An equiaxed ultra-fine grained structure with the mean grain size of $~50 \mutextrm{m}$ was obtained by four repetitive ECAP at 473 K. The microhardness of P/M 6061 Al alloy was drastically increased from about 40 Hv to 80 Hv by two repetitive ECAP at 373 K. However, the microhardness decreased with increasing ECAP temperature. The tensile stength of as-hot-pressed P/M 6061 Al alloy before ECAP was 95 MPa, whereas it increased to both 248 MPa after two repetitive ECAP at 373 K and 130 MPa after four repetitive ECAP at 473 K. The tensile properties of the ECAPed sample were compared with those of commercial cast 6061-O and 6061-T4 Al alloys.

Age-Hardening Behavior of SiCp Reinforced 6061 Aluminum Alloy Composites (SiCp/6061Al합금복합재료의 시효거동)

  • An, Haeng-Geun;Yu, Jeong-Hui;Kim, Seok-Won;U, Gi-Do
    • Korean Journal of Materials Research
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    • v.10 no.12
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    • pp.793-798
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    • 2000
  • The age-hardening behavior of unreinforced 6061 Al alloy and SiCp/6061 Al alloy composites reinforced with different size of SiC particle (average diameter ; 0.7$\mu\textrm{m}$ and 7.0$\mu\textrm{m}$) was investigated by hardness measurement, calorimetric technique and transmission electron microscopy. At 17$0^{\circ}C$ isothermal aging treatment, the peak aging time of 0.7$\mu\textrm{m}$SiCp/6061Al alloy composite and 7.0$\mu\textrm{m}$SiCp/6061Al alloy composite is shorter than that of unreinforced 6061Al alloy, and the aging of 7.0$\mu\textrm{m}$SiCp/6061Al alloy composite is accelerated more than that of 0.7$\mu\textrm{m}$SiCp/6061Al alloy composite. This acceleration is due to the increase of dislocation density by the compositeness with SiCp and the SiC particle size. In the peak aged condition, the major strengthening phase of these materials is intermediate $\beta$ phase(Mg$_2$Si), and the activation energy for the formation of $\beta$ phase is considerably decreased by the compositeness with SiCp and the increasing of SiC Particle site.

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High Temperature Plastic Deformation Condition of Al 6061 Alloy (Al 6061 합금의 고온 소성변형 조건에 관한 연구)

  • 김성일;정태성;유연철;오수익
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1998.03a
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    • pp.76-79
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    • 1998
  • High temperature plastic deformation behavior of Al 6061 alloy was characterized by hot torsion test. The Al 6061 alloy deformed continuously in the temperature range of 400∼550$^{\circ}C$, and strain rate range of 0.05∼5/sec. The softening mechanism of Al 6061 alloy was dynamic recrystallization and identified by hyperbolic sine law and zener-Hollmon parameter. The evolution of grain size and deformation resistance were calculated by the relationships of deformation variables.

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Wear Characteristics of Lubricant with Nano-diamond Particles on Al-6061 Aluminum Alloy (나노 다이아몬드 입자를 첨가한 엔진 오일의 알루미늄 6061 합금에 대한 마모 특성)

  • Hwang, Sung-Wan
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.12
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    • pp.16-23
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    • 2021
  • Pin-to-disc wear testing experiments were conducted to investigate the wear characteristics of commercial oil (5W-40) with nano-diamond particles. The upper specimen was a SUJ-2 high-carbon chromium steel ball with a diameter of 4 mm, and the lower specimen was made of the Al-6061 alloy. The applied load was 5 N, and the sliding speed was 0.25 m/s. The wear tests were conducted at a sliding distance of 500 m. The friction coefficients and wear rates of the Al-6061 specimens were tested using commercial oil with different nano-diamond concentrations ranging from 0 to 0.02 wt.%. The addition of nano-diamond particles to commercial oil reduced both the wear rate and coefficient of friction of the Al-6061 alloy. The use of nano-diamond particles as a solid additive in oil lubricants was found to improve the tribological behavior of the Al-6061 alloy. For the Al-6061 alloy, the optimal concentration was found to be 0.005 wt.% in view of the friction coefficient and wear rate. Further investigation is needed to determine the optimal concentration of nano-diamond particles for various loadings, sliding speeds, oil temperatures, and sliding distances.

An Investigation of Sliding Wear and Microstructural Evolution of Ultra-Eine Grained 6061 Al Alloy Fabricated by ARB (누적압연접합에 의한 6061 Al 합금의 결정립 미세화와 마멸 특성 연구)

  • Lee T.O.;Kim Y.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.05a
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    • pp.147-150
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    • 2001
  • The ARB (Accumulative Rolling Bonding) Process was applied to a 6061 Al alloy to obtain ultra-fine grains. After 4 ARB cycles at $315^{\circ}C$, original equilibrium large grains were transformed to ultra-fine grains of several hundred nano-meter size with nonequilibrium grain boundaries. At lower number of cycles, microsutcture of highly-tangled dislocation cells were observed. Large grains and coarsened precipitates filled the microstructure of specimens experienced ARB cycles more than 5. Sliding wear tests using a pin-on-disk type wear tester were conducted on the ARB processed 6061 Al alloy plate. Wear rates of the 6061 Al alloy increased with the increase of ARB cycle number as well as the applied load. Worn surfaces and debris, cross-sections of the worn specimen were examined with scanning electron microscopy (SEM) to investigate the wear mechanism of the ultra-fine grained 6061 Al Tensile properties of the 6061 Al alloy were also studied and used to correlate the wear test results with the microstructures, which evolved continuously with the number of ARB cycles.

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Thermal Stability and Dry Sliding Wear Behavior of Ultra-Fine Grained 6061 Al Alloy Processed by the Accumulative Roll-Bonding Process (누적압연접합 공정에 의해 제조된 초미세립 6061 Al 합금의 열적 안정성과 건식 미끄럼 마멸 거동)

  • Kim Y.S.
    • Transactions of Materials Processing
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    • v.14 no.1 s.73
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    • pp.71-77
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    • 2005
  • Thermal stability and dry sliding wear behavior of ultra-fine grained 6061 Al alloy fabricated by an accumulative roll-bonding (ARB) process have been investigated. After 4 ARB cycles, an ultra-fine grained microstructure of the 6061 Al alloy composed of grains with average size of 500nm, and separated mostly by high-angle boundaries was obtained. Though hardness and tensile strength of the ARB processed Al alloy increased with ARB cycles up to 4 cycles, the processed alloy exhibited decreased ductility and little strain hardening. Thermal stability of the ARB-processed microstructure was studied by annealing of the severely deformed alloy at $423K{\sim}573K$. The refined microstructure of the alloy remained stable up to 473K, and the peak aging treatment of the alloy at 450K for 8 hrs increased the thermal stability of the alloy. Sliding-wear rates of the alloy increased with the number of ARB cycles in spite of the increased hardness with the cycles. Wear mechanisms of the ultra-fine grained alloy were investigated by examining worn surfaces, wear debris, and cross-sections by a scanning electron microscopy (SEM).

A Study on the Weldability and the Fatigue Characteristics in Resistance pot Welding of 5182-O/6061-T6 Dissimilar Aluminum Alloy Sheets (이종 AI합금의 저항점용접부 용접성과 피로특성에 관한 연구)

  • 박진철;정원욱;강성수
    • Journal of Welding and Joining
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    • v.17 no.2
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    • pp.44-52
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    • 1999
  • This study deals with spot weld ability of dissimilar aluminum alloy sheets in order to take advantage of its lightweight and strength. The paper also shows the relationship between weld elements(i.e. current, welding time and tip force) and weld quality on the resistance spot weld part of the same and dissimilar Al alloy. The conclusions are: (1) Because of excessive tip force, deep indentation remained at the Al 5182 side which is lower stiffness at the dissimilar Al alloy. (2) Weld quality (i.e. tensile shear strength) of dissimilar Al alloy is superior to that of the same Al 6061 alloy. (3) As long cycles, fatigue life of spot weld specimen on dissimilar Al alloy sheets was better than that of the same Al alloy.

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Analysis of Microstructure and Mechanical Properties According to Heat Treatment Conditions in GMAW for Al 6061-T6 Alloy (Al 6061-T6 합금의 MIG 용접 후 열처리조건에 따른 미세조직 및 기계적 물성 분석)

  • Kim, Chan Kyu;Cho, Young Tae;Jung, Yoon Gyo;Kang, Shin Hyun
    • 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.

Effects of Two-Step Aging Treatment on the Mechanical Properties of 6061 Al Alloy (A 6061 합금의 기계적 특성에 미치는 2단시효의 영향)

  • Lee, Bo-Bae;Im, Hang-Joon;Jeong, Geol-Chae.
    • 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 $120^{\circ}C$.

A Study on the Mechanical Characteristic in Al 6061 Alloys welded by Friction Stir Welding (Al 6061 합금의 마찰교반접합시 접합부의 역학적 특성에 관한 연구)

  • 방한서;김흥주;고민성;장웅성
    • 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.