Manufacturing Technology Today

Open Access Open Access  Restricted Access Subscription Access
Open Access Open Access Open Access  Restricted Access Restricted Access Subscription Access

Effects of Scandium Addition on Microstructure and Mechanical Properties of AA 7075 Aluminium Alloy


Affiliations
1 Welding Research Center, KLS VDRIT, Haliyal, India
2 Department of Mechanical Engineering, Research Center, SDMCET, Dharwad, India
     

   Subscribe/Renew Journal


The most attractive properties of aluminum and its alloys which make them suitable for a wide variety of applications are their light weight, appearance, frabricability, strength, and corrosion resistance. Among aluminium alloys AA7075 alloy has many attractive properties compared to other alloy it is economical and versatile to use this is the reason it is very widely used in the aerospace, automobile and other industries. AA7075 aluminum alloys are important structural materials due to their high strength and increased strength to weight ratio. The effects of Sc addition on the microstructure and mechanical properties of the AA7075 wrought zinc alloy were investigated by using optical microscope, scanning electron microscopy, and tensile testing. The experimental results show that a minor Sc addition to AA7075 alloy has an obvious effect on the refinement of the microstructure of the AA7075 alloy. During casting, incomplete dynamic recrystallization occurs in all the alloys, and the recrystallized grains become much finer with increasing Sc addition. The ultimate tensile strengths of AA7075 evidently increase with the addition of Sc, but the elongations decrease. The AA7075 alloy with 0.23% (weight fraction) Sc addition is found to have the tensile strength of about 468.8 MPa and the yield strength of about 324.3 MPa. Further by T6 tempering heat treatment, the tensile strength of the alloy containing 0.23% Sc is increased to 485.8 MPa and yield strength 335.49 Mpa.

Keywords

AA 7075 Alloy, Grain Refinement, Tensile Properties, Heat Treatment, Scandium.
User
Subscription Login to verify subscription
Notifications
Font Size

  • Norman, AF; Prangnell, PB; Mcewen, RS: The solidifi cation behavior of dilute aluminum-scandium alloys, 'Acta Materialia', 1998, 46(16): 5715-5732.

  • Rokhlin, LL; Dobatkina, TV; Bochvar, NR; Lysova, EV: Investigation of phase equilibrium in alloys of the Al-Zn-Mg-CuZr-Sc system, 'Journal of Alloys and Compounds', 2004, 367:10-16.

  • Glenn, AM; Russo, SP; Gorman, JD; Paterson, PJK: The effect of grain refining on the micro-segregation of aluminum magnesium alloy 5182, 'Micron', 2001, 32: 841-850.

  • Norman, AF; Hyde, K; Costello, F; Thompson, H; Birley, S; Prangnell, PB: Examination of the effect of Sc on 2000 and 7000 series aluminum alloy castings: for improvements in fusion welding, 'Materials Science and Engineering A', 2003, 354: 188-198.

  • Yang, JL: Neutron diffraction study on site occupation of substitutional elements at sub lattices in Fe3Al inter metallics, 'Materials Science and Engineering A', 1998, 258: 69-74.

  • Prasad, KS; Gokhale, AA; Mukhopadhyay, AK; Banerjee, D; Goel, DB: On the formation of faceted Al3Zr (β prime) precipitates in Al-Li-Cu-Mg-Zr alloys, 'Acta Materialia', 1999,47(8): 2581-2592.

  • Robson, JD; Prangnell, PB: Modeling Al3Zr dispersoids precipitation in multi-component aluminum alloys, 'Materials and Engineering A', 2002, 352: 240-250.

  • Suh, DW; Lee, SY; Lee, KW; Lim, SK; Oh KW: Microstructural evolution of Al-Zn-Mg-Cu-Sc alloy during hot extrusion and heat treatments, 'Journal of Materials Processing Technology', 2004, 155-156: 1330-1336.

  • Furukawa, M; Utsunomiya, A; Matsubara, K; Horita, Z: Influence of magnesium on grain refinement and ductility in a dilute Al-Sc alloy, 'Acta Materialia', 2001, 49: 3829-3838.

  • Iwamura, S; Miura, Y: Loss in coherency and coarsening behavior of Al3Sc precipitates, 'Acta Materialia', 2004, 52: 591-600.

  • Easton, MA; Stjohn, DH: A model of grain refinement incorporating alloy constitution and potency of heterogeneous nucleate particles, 'Acta Materialia', 2001, 49: 1867-1878.

  • Murty, BS, Kori, SA, Venkateswarlu, K; Bhat, RR; Chakraborty, M: Manufacture of Al-Ti-B master alloys by the reaction of complex halide salts with molten aluminum, 'Journal of Materials Processing Technology', 1999, 89-90: 152-158.

  • Temmar, M; Hadji, M; Sahraoui, T: Effect of post-weld aging treatment on mechanical properties of Tungsten Inert Gas welded low thickness 7075 aluminium alloy joints, 'Materials and Design', 32, 2011, 3532–3536.

  • Villars, P; Calvert, LD: Pearson´s Handbook of Crystallographic Data for Inter-metallic Phase. Metals Park, Oh: American Society for Metals, USA, 1985.

  • Greer, AL; Bunn, AM; Tronche, A; Evans, PV; Bristow, DJ: Modeling of inoculation of metallic melts: application to grain refi nement of aluminum by Al-Ti-B, 'Acta Materialia', 2000, 48: 2823-2835


Abstract Views: 271

PDF Views: 7




  • Effects of Scandium Addition on Microstructure and Mechanical Properties of AA 7075 Aluminium Alloy

Abstract Views: 271  |  PDF Views: 7

Authors

K. S. Pujari
Welding Research Center, KLS VDRIT, Haliyal, India
D. V. Patil
Department of Mechanical Engineering, Research Center, SDMCET, Dharwad, India
Akash Maney
Welding Research Center, KLS VDRIT, Haliyal, India
A. Abhishek
Welding Research Center, KLS VDRIT, Haliyal, India
K. Kartik
Welding Research Center, KLS VDRIT, Haliyal, India
H. Chetan
Welding Research Center, KLS VDRIT, Haliyal, India

Abstract


The most attractive properties of aluminum and its alloys which make them suitable for a wide variety of applications are their light weight, appearance, frabricability, strength, and corrosion resistance. Among aluminium alloys AA7075 alloy has many attractive properties compared to other alloy it is economical and versatile to use this is the reason it is very widely used in the aerospace, automobile and other industries. AA7075 aluminum alloys are important structural materials due to their high strength and increased strength to weight ratio. The effects of Sc addition on the microstructure and mechanical properties of the AA7075 wrought zinc alloy were investigated by using optical microscope, scanning electron microscopy, and tensile testing. The experimental results show that a minor Sc addition to AA7075 alloy has an obvious effect on the refinement of the microstructure of the AA7075 alloy. During casting, incomplete dynamic recrystallization occurs in all the alloys, and the recrystallized grains become much finer with increasing Sc addition. The ultimate tensile strengths of AA7075 evidently increase with the addition of Sc, but the elongations decrease. The AA7075 alloy with 0.23% (weight fraction) Sc addition is found to have the tensile strength of about 468.8 MPa and the yield strength of about 324.3 MPa. Further by T6 tempering heat treatment, the tensile strength of the alloy containing 0.23% Sc is increased to 485.8 MPa and yield strength 335.49 Mpa.

Keywords


AA 7075 Alloy, Grain Refinement, Tensile Properties, Heat Treatment, Scandium.

References