Grain refinement limit and mechanical properties of 6063 alloy inoculated by Al–Ti–C (B) master alloys

Abstract The grain refinement limit of 6063 alloy inoculated by Al–5Ti–0.25C and Al–5Ti–1B master alloys and the impact of grain size on the mechanical properties, including the tensile strength and hardness, are investigated in the present article. It is revealed that the smallest average grain size of 6063 alloys refined by these two master alloys is the same under the present experimental condition, thus the grain refinement limit of 6063 alloy is 40 μm. However, the limit addition of the two master alloys corresponding to the grain refinement varies at 2.0 wt.% and 3.0 wt.% for Al–5Ti–0.25C and Al–5Ti–1B, respectively, and the grain refining performance of the former is much better than that of the later one before reaching the refinement limit. Furthermore, the mechanical properties of 6063 alloy are also improved first with the grain refinement, but turn to decrease after the same 1.5 wt.% addition both for Al–5Ti–0.25C and Al–5Ti–1B. The highest ultimate tensile strength (UTS) and hardness (HB) of 6063 alloy obtained by the refinement of Al–5Ti–0.25C and Al–5Ti–1B are 271 MPa, 81.7 and 250 MPa, 80, respectively. Thus the UTS and hardness of 6063 alloy refined by the former master alloy are also much higher than those refined by the later one. It is worthy to note that the 6063 alloys with the smallest average grain size did not behave the highest mechanical properties and the possible mechanisms are also discussed.

[1]  P. Uggowitzer,et al.  The influence of MgSi particle reactivity and dissolution processes on corrosion in Al–Mg–Si alloys , 2008 .

[2]  P. Schaffer,et al.  Settling behaviour of different grain refiners in aluminium , 2005 .

[3]  S. Wieczorek,et al.  Kinetics of transformation during supersaturation and aging of the Al-4.7mass%Cu alloy: Grain size, dilatometric, and differential thermal analysis studies , 2005 .

[4]  Y. Birol.  Production of Al–Ti–B master alloys from Ti sponge and KBF4 , 2007 .

[5]  Ping Zhang,et al.  Influence of a new kind of Al–Ti–C master alloy on the microstructure and mechanical properties of Al–5Cu alloy , 2014 .

[6]  Xiurong Zuo,et al.  Effect of B/Ti mass ratio on grain refining of low-titanium aluminum produced by electrolysis , 2006 .

[7]  Tu Ying-hong,et al.  Some suggestions about the revision of the National Standard GB/T228-2002 "Metallic materials-Tensile testing at ambient temperature" , 2009 .

[8]  P. Grant,et al.  Influence of cooling rate on the Fe intermetallic formation in an AA6063 Al alloy , 2013 .

[9]  B. Billia,et al.  Determination of the average nucleation undercooling of primary Al-phase on refining particles from Al-5.0 wt% Ti-1.0 wt% B in Al-based alloys using DSC , 2009 .

[10]  W. Zhenqing,et al.  The relationship between microstructures and refining performances of Al–Ti–C master alloys , 2002 .

[11]  N. Mahallawy,et al.  Wear properties of ECAP-processed ultrafine grained Al–Cu alloys , 2010 .

[12]  Baode Sun,et al.  A quantitative study of solute diffusion field effects on heterogeneous nucleation and the grain size of alloys , 2011 .

[13]  G. González,et al.  Effect of 0.1% vanadium addition on precipitation behavior and mechanical properties of Al-6063 commercial alloy , 2006 .

[14]  A. L. Greer,et al.  Effect of instability of TiC particles ongrain refinement of Al and Al–Mg alloysby addition of Al–Ti–C inoculants , 2000 .

[15]  J. Cui,et al.  Effect of vanadium on the microstructures and mechanical properties of an Al–Mg–Si–Cu–Cr–Ti alloy of 6XXX series , 2013 .

[16]  L’Heureux.  Oscillatory zoning in crystal growth: A constitutional undercooling mechanism. , 1993, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[17]  S. Babu,et al.  Effect of grain size refinement and precipitation reactions on strengthening in friction stir processed Al–Cu alloys , 2011 .

[18]  A. Kennedy,et al.  The thermal stability of TiC particles in an Al7wt.%Si alloy , 2003 .

[19]  B. S. Murty,et al.  Development of Al-Ti-C grain refiners and study of their grain refining efficiency on Al and Al-7Si alloy , 2005 .

[20]  A. L. Greer,et al.  The effect of the size distribution of inoculant particles on as-cast grain size in aluminium alloys , 2004 .

[21]  V. Stolyarov,et al.  Ultrafine-grained Al-5 wt.% Fe alloy processed by ECAP with backpressure , 2003 .

[22]  C. Liu,et al.  Micromechanical properties of high fracture performance SiCp–6061Al/6061Al composite , 2002 .

[23]  Peter Schumacher,et al.  Grain Refinement of Aluminium Alloys by Inoculation , 2003 .

[24]  Xiangfa Liu,et al.  The effect of melting temperature and time on the TiC particles , 2009 .

[25]  S. Nam,et al.  Enhancement of mechanical properties of Al–Mg–Si alloys by means of manganese dispersoids , 1999 .

[26]  H. Ding,et al.  Influence of zirconium on grain refining efficiency of Al–Ti–C master alloys , 2007 .

[27]  David H. StJohn,et al.  Grain refinement of aluminum alloys: Part II. Confirmation of, and a mechanism for, the solute paradigm , 1999 .

[28]  B. Bai,et al.  Performance comparison of AlTiC and AlTiB master alloys in grain refinement of commercial and high purity aluminum , 2006 .

[29]  D. StJohn,et al.  A model of grain refinement incorporating alloy constitution and potency of heterogeneous nucleant particles , 2001 .