Synthesis of TiAl(Cr)/Ti<SUB>2</SUB>AlC Composites by Reactive Arc-Melting

Abstract

TiAl(Cr)/Ti 2 AlC composites have been prepared by a reactive arc-melting technique using elemental powders of Ti, Al, Cr and C. Resulting composites have been reinforced using 3.5, 10 and 18 vol% Ti 2 AlC in a matrix of TiAl with and without addition of Cr. The axial ratio of γ -phase has been lowered through the complete solid solution of chromium. The grain size of the matrix has been found to decrease whereas its distribution converges along the content of Ti 2 AlC. The lamella grains in the matrix have been changed both into TiAl and very fine Ti 2 AlC particles by a homogenizing treatment. Compared to TiAl single-phase alloy, studied composite materials have revealed superior mechanical properties, such as bending strength, compressive strength and fracture toughness. This improvement is caused by the formation of Cr solid-solution for hardening, dispersion of the Ti 2 AlC particles and the fine grain of the TiAl matrix.

Microstructure and Dry Sliding Wear of Ti-50Al Alloy and Ti-47Al-3W/Ti<SUB>2</SUB>AlC Composite Produced by Reactive Arc-Melting

“…A reactive arc-melting technique as reported elsewhere 9,17,18) was used to fabricate the Ti-50Al alloys and Ti-47Al-3W/Ti 2 AlC composites. The powders prepared are high purity elemental powders of titanium (99.5%, À350 mesh), aluminum (99.9%, À150 mesh), tungsten (99.95%, particle size; $1mm), and carbon (graphite, 99.99%, À400 mesh).…”

“…7) It is also possible to form an intermetallic matrix composite with full density having ceramic dispersions using the reactive arc-melting technique. 8,9) In the present work, Ti50Al alloys and Ti-47Al-3W/Ti 2 AlC intermetallic composites were produced using this technique. The reinforcement Ti 2 AlC particles is accomplished by means of a combustion reaction.…”

Electric Current‐Assisted Synthesis of the Ti2AlC MAX Carbide Phase by Arc Melting and Heat Treatment Using Spark Plasma Sintering

“…extensively studied for the synthesis of the MAX phases in the Ti-Al-C system, although a few articles focusing on the synthesis of Ti 2 AlC-containing Ti-Al-Cr alloy composites have been published. [19][20][21] Phase transformations in the Ti-Al-C system were studied by Sleptsov et al [22] with samples synthesized by reactive arc melting containing both MAX phases and intermetallic phases. The synthesized MAX phases were stable in a large range of temperature, from 650 C to the solidus temperature of 1405 C. Thermodynamic calculations showed that after that temperature the amount of Ti 2 AlC in the sample decreased, disappearing at %1580 C, whereas the amount of liquid phase and Ti 3 AlC 2 increased up until 1770 C, where only the liquid phase and TiC xÀ1 remained.…”

Microstructure and Dry Sliding Wear of Ti-50Al Alloy and Ti-47Al-3W/Ti<SUB>2</SUB>AlC Composite Produced by Reactive Arc-Melting

“…7) It is also possible to form an intermetallic matrix composite with full density having ceramic dispersions using the reactive arc-melting technique. 8,9) In the present work, Ti-50Al alloys and Ti-47Al-3W/Ti 2 AlC intermetallic composites were produced using this technique. The reinforcement Ti 2 AlC particles is accomplished by means of a combustion reaction.…”