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چکیده
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In-situ Al matrix composite was synthesized from Al–TiO2–C powder mixtures using mechanical alloying and heat treatment, subsequently. The effect of ball milling on reaction processes of the resulting nanocomposite was investigated. The evaluation of powder mixture without mechanical activation showed that at 900°C aluminum reduced TiO2, forming Al3Ti and Al2O3. After 20 h mechanical activation of powder mixture, Al3Ti and Al2O3 were fabricated. After that, by increasing milling time up to 30 h, no new phases formed. The DTA analysis of 30 h milled powder indicated two peaks after aluminum melting at 730 and 900°C. The XRD results confirmed that at 730°C, molten Al reacted with TiO2 and C, forming Al3Ti, Al2O3 and Al4C3. After that, at 900°C, Al3Ti reacted with Al4C3, causing TiC formation. This results proposed that the TiC formation is associated by a series of reactions between intermediate products, Al3Ti and Al4C3 and the resultant nanocomposite was successfully synthesized after 30 h milling and heated by DTA analysis up to 1200°C.
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