Vol.60, Nos. 2-3 - Indira Gandhi Centre for Atomic Research
Vol.60, Nos. 2-3 - Indira Gandhi Centre for Atomic Research
Vol.60, Nos. 2-3 - Indira Gandhi Centre for Atomic Research
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Trans. Indian Inst. Met.<br />
<strong>Vol.60</strong>, <strong>Nos</strong>. 2-3, April-June 2007, pp. 355-360<br />
TP 2152<br />
Solidification of Hybrid Aluminium Alloy Matrix Composites<br />
B.C. Pai, T.P.D. Rajan and R.M. Pillai<br />
Materials and Minerals Division<br />
National Institute <strong>for</strong> Interdisciplinary Science and Technology,<br />
(Formerly Regional <strong>Research</strong> Laboratory (CSIR))<br />
Thiruvananthapuram-695 019, Kerala, India<br />
E-mail: bcpai12@rediffmail.com<br />
(Received 30 June 2006 ; in revised <strong>for</strong>m 20 November 2006)<br />
ABSTRACT<br />
Hybrid metal Matrix Composites (HMMC) are second generation composites containing more than one type, shape and size of<br />
rein<strong>for</strong>cements in the matrix alloy. These composites offer combined properties of the rein<strong>for</strong>cements, some times improved and<br />
special properties with synergistic effects. The properties of these composites depend strongly on the distribution profile of the<br />
rein<strong>for</strong>cements. However, the nature of the distribution of the rein<strong>for</strong>cements depends on the size, shape and the morphology of the<br />
rein<strong>for</strong>cements and their sequence of addition. The other factors affecting the solidification conditions and microstructure of the<br />
composites are thermal characteristics of the rein<strong>for</strong>cements and the interfacial reaction taking place between the rein<strong>for</strong>cements and<br />
the matrix. In the present investigation, the hybrid composites are synthesized by stir casting technique and solidification behavior<br />
of hybrid Al-SiC p<br />
-graphite particle rein<strong>for</strong>ced composites is studied using thermal analysis and Differential thermal analysis (DTA)<br />
and compared with corresponding microstructures.<br />
Trans. Indian Inst. Met.<br />
<strong>Vol.60</strong>, <strong>Nos</strong>. 2-3, April-June 2007, pp. 361-365<br />
TP 2153<br />
A Thermodynamic Assessment of the Inoculation<br />
Process in Al-base Alloys<br />
L. Magnusson and H. Fredriksson<br />
KTH ITM/MSE Materials Processing, 100 44 Stockholm, Sweden<br />
E-mail: lenam@matpr.kth.se<br />
(Received 30 June 2006 ; in revised <strong>for</strong>m 20 November 2006)<br />
ABSTRACT<br />
The binary Al-Ti and the ternary phase diagrams Al-Ti-B and Al-Ti-C are calculated from normal thermodynamic laws. The calculated<br />
phase diagrams are used to discuss the <strong>for</strong>mation of Al 3<br />
Ti during the cooling process. In the binary Al-Ti phase diagram an<br />
undercooling of only 30 K is shown to be necessary to nucleate new crystals of Al 3<br />
Ti. It is shown that both Al 3<br />
Ti and TiB 2<br />
are <strong>for</strong>med<br />
during cooling of an inoculated Al-melt. TiB 2<br />
is more easily nucleated than Al 3<br />
Ti due to its lower solubility product. Al 3<br />
Ti is assumed<br />
to be nucleated on the TiB 2<br />
particles. TiC is not stable at the melting point of aluminium and will decompose into Al 4<br />
C 3<br />
and Al 3<br />
Ti<br />
during cooling. It is suggested that Al 3<br />
Ti is the active reagent <strong>for</strong> nucleation of Al.