Microstructure and compression behavior of in-situ synthesized Ti2AlC reinforced Ti-48Al-2Cr alloy with carbon nanotubes addition

Abstract Different contents of carbon nanotubes (CNTs) were added into Ti-48Al-2Cr alloys (at.%) to obtain in-situ synthesized Ti2AlC particles by vacuum arc melting. The effect of the CNT content in the range of 0-1.5 wt.% on the microstructure and compression behavior were systematacially investigated, especially the controlling mechanism of the Ti2AlC phase. The experimental results showed that the volume fraction of the Ti2AlC phase increases with increasing CNT content. The lamellar spacing of the microstructure and the length-diameter ratio of the Ti2AlC phase decreases as the CNT content increases. The compressive strength and strain first increase and then decrease with increasing CNT content. When the mass fraction of CNT is 1.0, the maximum compressive strength is 1904.25 MPa and the maximum strain is 9.84%, respectively, which is 37.9% and 53.9% higher than that of the Ti-48Al-2Cr alloy. The controlling mechanism of mechanical properties of Ti-48Al-2Cr-xCNT alloy is the combination of fine grain strengthening and γ phase weakening.