The Effects of Defects on Tensile Properties of Cast ADC12 Aluminum Alloy

详细信息    查看全文

• 作者：Mitsuhiro Okayasu ; Hikoyuki Sakai
• 刊名：Metallurgical and Materials Transactions A
• 出版年：2015
• 出版时间：November 2015
• 年：2015
• 卷：46
• 期：11
• 页码：5418-5430
• 全文大小：3,994 KB
• 参考文献：1.M.A. Irfan, D. Schwam, A. Karve, R. Ryder, Porosity reduction and mechanical properties improvement in die cast engine blocks, Mater. Sci. Eng. A 535(2012)108-14.CrossRef
  2.C.H. Caceres, Economical and environmental factors in light alloys automotive applications, Metall. Mater. Trans A 38A(2007)1649-661.CrossRef
  3.H.R. Ammar, A.M. Samuel, F.H. Samuel, Porosity and the fatigue behavior of hypoeutectic and hypereutectic aluminum-silicon casting alloys, Int. J. Fatigue 30(2008)1024-035.CrossRef
  4.O. Kuwazuru, Y. Murata, Y. Hangai, T. Utsunomiya, S. Kitahara, N. Yoshikawa, X-ray CT inspection for porosities and its effect on fatigue of die cast aluminum alloy, J. Solid Mech. Mater. Eng. 9(2008)1220-231.CrossRef
  5.A.K.M. Aziz Ahamed, H. Kato, Influence of casting defects on tensile properties of ADC12 aluminum alloy die-castings, Mater. Trans. JIM 49(2008)1621-628.CrossRef
  6.S. Jana, R.S. Mishra, J.B. Baumann, G. Grant, Effect of friction stir processing on fatigue behavior of an investment cast Al-Si-.6 Mg alloy, Acta Mater. 58(2010)989-003.CrossRef
  7.G.W. Mugica, D.O. Tovio, J.C. Cuyas, A.C. Conzátes, Effect of porosity on the tensile properties of low ductility aluminum alloys, Mater. Res. 7(2004)221-29.CrossRef
  8.H.D. Zhao, F. Wang, Y.Y. Li, W. Xia, Experimental and numerical analysis of gas entrapment defects in plate ADC12 die castings, J. Mater. Process. Technol. 209(2009)4537-542.CrossRef
  9.C. Kawai, A. Yamakawa, Effect of porosity and microstructure on the strength of Si3N4: designed microstructure for high strength, high thermal shock resistance, and facile machining, J. Am. Ceram. Soc. 80(1997)2705-708.CrossRef
  10.J.P. Weiler, J.T. Wood, Modeling fracture properties in a die-cast AM60B magnesium alloy II -The effects of the size and location of porosity determined using finite element simulations, Mater. Sci. Eng. A 527(2009)32-7.CrossRef
  11.J.P. Weiler, J.T. Wood, Modeling fracture properties in a die-cast AM60B magnesium alloy I -Analytical failure model, Mater. Sci. Eng. A 527(2009)25-1.CrossRef
  12.C.H. Cáceres, B.I. Selling, Casting defects and the tensile properties of an Al-Si-Mg alloy, Mater. Sci. Eng. A 220(1996)109-16.CrossRef
  13.M. Avalle, G. Belingardi, M.P. Cavatorta, R. Doglione, Casting defects and fatigue strength of a die cast aluminum alloy: a comparison between standard specimens and production components, Int. J. Fatigue 24(2002)1-.CrossRef
  14.M. Okayasu, S. Takeuchi, M. Yamamoto, H. Ohfuji, Precise analysis of microstructural effects on mechanical properties of cast ADC12 aluminum alloy, Metall. Mater. Trans A, 46A(2015)1597-609.CrossRef
  15.M. Okayasu, S. Takasu, M. Mizuno, Relevance of instrumented nano-indentation for the assessment of the mechanical properties of eutectic crystals and α-Al grain in cast aluminum alloys, J. Mater. Sci. 47(2012)241-50.CrossRef
  16.W.C. Oliver, G.M. Pharr, Measurement of harness and elastic modulus by instrumented indentation: Advances in understanding and refinements to methodology, J. Mater. Res. 19(2004)3-0.CrossRef
  17.A. Ueno, S. Miyakawa, K. Yamada, T. Sugiyama, Fatigue behavior of die casting aluminum alloys in air and vacuum, Procedia Eng. 2(2010)1937-943.CrossRef
  18.Q. Yan, H. Yu, Z. Xu, B. Xiong, C. Cai, Effect of holding pressure on the microstructure of vacuum counter-pressure casting aluminum alloy, J. Alloy. Comp. 501(2010)352-57.CrossRef
  19.M. Okayasu, Y. Ohkura, S. Takeuchi, S. Takasu, H. Ohfuji, T. Shiraishi, A study of the mechanical properties of an Al-Si-Cu alloy (ADC12) produced by various casting processes, Mater. Sci. Eng. A 543(2012)185-92.CrossRef
  20.N. Nakata, Y.G. Kim, H. Fujii, T. Tsumura, T. Komazaki, Improvement of mechanical properties of aluminum die casting alloy by multi-pass friction stir processing, Mater. Sci. Eng. A 437(2006)274-80.CrossRef
  
• 作者单位：Mitsuhiro Okayasu (1)
  Hikoyuki Sakai (2)
  
  1. Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama, 700-8530, Japan
  2. Department of Materials Science and Engineering, Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime, 790-8577, Japan
  
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Materials Science
  Metallic Materials
  Structural Materials
  Physical Chemistry
  Ceramics,Glass,Composites,Natural Materials
  
• 出版者：Springer Boston
• ISSN：1543-1940

文摘

To better understand the effects of cast defects on mechanical properties, cast aluminum alloys with various porosities were used. Porosity in the cast samples was created during the casting process, and to clearly identify the porosity effects on the mechanical properties, artificial defects (porosity-like tiny holes) were created mechanically. The tensile properties for the cast aluminum alloys appear to be attributed to the area fraction of the porosity on the fracture surface (namely, the defect rate, DR), although there were different trends because of the different stress concentrations: the ultimate tensile strength and 0.2 pct proof strength were linearly related to DR, while a non-linear correlation was detected for fracture strain. Even in Al alloys with small amounts of defects, significant reductions in the fracture strain were observed. These results were verified using tensile tests on specimens containing artificial defects. The effects of artificial defects on the tensile properties were further investigated using numerous tiny holes, created in several formations. The artificial defects (several small holes), lined up at perpendicular (90 deg) and 45 deg directions against the loading direction, made significant reductions in the tensile properties, even though only weak defect effects were observed for the 90 deg loading direction. No severe defect effects were obvious for the specimen with a tiny defect of ?0.1 mm, because of the lower stress concentration, compared to the microstructural effects in the cast Al alloys: the grain boundaries and the second phases. Such phenomena were clarified using tensile tests on cast samples with differently sized microstructures. There were no clear defect effects on the yield strength as the defect amount was less than 10 pct, and microstructural effects were not detected either in this case. Failure characteristics during tensile loading were revealed directly by in-situ strain observations using high-speed cameras. Manuscript submitted January 19, 2015.