Grain Refinement of Al₃Ti Dispersed Aluminum Matrix Composites by Reaction Centrifugal Mixed-Powder Method

Abstract

Aluminum matrix composites having dispersoids of Al 3 Ti intermetallic compounds can be obtained by reaction centrifugal mixed-powder (RCMP) method. It is reported that Al 3 Ti intermetallic compounds act as grain refiners, since the disregistry value between Al 3 Ti intermetallic compound phase and Al matrix is smaller than 10%. In terms of lattice registry between Al matrix and Al 3 Ti phase, it is expected that the grain structure of Al matrix in Al-Al 3 Ti composites becomes more refined than that of centrifugally cast pure Al. In this study, Al-Al 3 Ti composites have been cast by the RCMP method. Effects of the Al 3 Ti phases around Ti particles formed by reaction between Al and Ti particles during RCMP method on grain refinement behavior of Al matrix have been systematically investigated. Moreover, grain refining performance of Al cast by Al-Ti refiner with grain shaped Ti particles was also studied.

New Processing Routes for Functionally Graded Materials and Structures through Combinations of Powder Metallurgy and Casting

“…Finally, ring-or disc-shaped FGMs or structures having dispersion particles distributed in the outer part of the cast sample can be obtained as shown in Figure 2(e). FGMs, such as Cu/ SiC [12], Al/TiO 2 [12], and Al/Al 3 Ti/Ti [15], were obtained with this processing method in our previous studies.…”

“…As new melt processing techniques, centrifugal mixed-powder method [12][13][14][15] and centrifugal sintered-casting method [16,17] have been recently developed. These two melt processing techniques are introduced in this chapter.…”

Improvement of bonding force between abrasive grains and matrix in Cu/diamond composite fabricated by centrifugal mixed-powder method

“…In our previous studies (El-Hadad et al, 2011;Yamauchi et al, 2015), Al matrix composites containing Al 3 Ti particles have been fabricated by reaction CMPM. In this fabrication process, mixed-powder of Al and Ti particles is prepared and then molten Al is poured into the spinning mold with this mixed-powder.…”

“…In addition, Watanabe et al (2013) have developed centrifugal sintered-casting, which is CMPM combined with sintering process, and have successfully fabricated Al-based diamond grinding wheel. Also, Kunimine et al (2015) have prepared Cu-based diamond grinding wheel by the centrifugal sintered-casting, and they could make holes for the CFRP. Therefore, the CMPM is effective technique to fabricate the grinding wheel.…”

Heterogeneous nucleation of α-Al primary crystal on L12modified Al2.7Ni0.3Ti phase

“…However, many of them have been contradicted. Among them, we believe that the Al 3 Ti particles in the refiners act as the centers of heterogeneous nucleation in the mechanism of grain refinement, [11][12][13][14] where Al 3 Ti has a low-symmetry tetragonal D0 22 structure and its lattice parameters are a = 0.3851 nm and c = 0.8608 nm, while the Al phase has an fcc structure with a = 0.4049 nm.…”