Effects of Platelet Size and Mean Volume Fraction on Platelet Orientation and Volume Fraction Distributions in Functionally Graded Material Fabricated by a Centrifugal Solid-Particle Method

Abstract

Background. A centrifugal solid-particle method has been successfully used as a means to fabricate functionally graded materials (FGMs). Various processing parameters significantly influence the formation of the graded microstructural and properties distribution in these FGMs. Method of Approach. Alloys with different Al3Ti platelet volume fractions and platelet sizes are used to study the effects of those parameters on graded distributions of the volume fraction and orientation of platelets. Al-platelet/plaster FGMs are used as a model system, and the effects of the same parameters are investigated. Results. It was found that an increase in initial volume fraction and particle size leads to steeper gradients of volume fraction and orientation distributions within the Al-Al3Ti FGMs. The results of the experimental studies are compared to those of the model material. Conclusions. It was verified that, although with some limitations, the proposed model system will be useful in the study of the formation mechanisms of the graded distributions in the FGMs.

Wear Properties of Intermetallic Compound Reinforced Functionally Graded Materials Fabricated by Centrifugal Solid-particle and In-Situ Methods

“…4. Here, one of the ordinates shows the Herman's orientation parameter, fp (9,10,19,20) , which ranges between values of fp = 0 (for a random distribution of the planes) and fp = 1 (for a perfect alignment). It is clearly seen that the orientation parameter increases proportionally to the normalized thickness.…”

“…Solid-Particle Method (17) Al-Al 3 Ti FGMs were fabricated using the centrifugal solid-particle method in a similar manner to that of previous studies (7)(8)(9)(10) . The master alloy ingot was a commercial aluminum alloy containing 5mass% Ti.…”

“…The first type is the centrifugal solid-particle method, in which the processing temperature is lower than the liquidus temperature of the master alloy, whereby the dispersed intermetallic particles are stable inside a liquid matrix (7)(8)(9)(10) . The other method is the centrifugal in-situ method (11)(12)(13)(14)(15)(16) , in which the processing is implemented under temperatures higher than the liquidus temperature of the master alloy.…”

“…As a result, in the case of the centrifugal in-situ method, the centrifugal force is applied to a completely liquid phase and the intermetallic compound particles crystallize from the liquid phase directly during the casting process. One product of the centrifugal solid-particle method is Al-Al 3 Ti FGM, which contains anisotropically oriented Al 3 Ti platelets in the Al matrix (7)(8)(9)(10) . Figure 1 shows a schematic representation of the arrangement of the Al 3 Ti platelets in an Al-Al 3 Ti FGM ring, which is the typical shape of the finished product fabricated by the centrifugal method.…”

Review Fabrication of Functionally Graded Materials under a Centrifugal Force

“…It is worthwhile to notice that the Al 3 Ti particles are oriented with their platelet planes nearly perpendicular to the radial direction of the ring. The graded distribution of orientation becomes steeper as the platelet size and mean volume fraction increases (Sequeira et al, 2007). In this way, the orientation of the Al 3 Ti platelets, as well as the mean volume fraction of the particles, was found to be gradually distributed in the Al/Al 3 Ti FGMs (Watanabe et al, 2001).…”