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Nearly pure Ti 3 AlC 2 powders have been synthesized by calcining a mixture of titanium, aluminum, and graphite powders using tin powders as additives. Four recipes with different mole ratios of Ti:Al:C:Sn were examined at calcining temperatures from 13001 to 15001C. The addition of Sn effectively inhibited the generation of thermal explosion when the volume of the starting materials is larger, and considerably reduced the lowerlimit calcining temperature. The nearly pure Ti 3 AlC 2 powders can be obtained reliably on a large scale by calcining the starting materials with a mole ratio of 3Ti:1Al:1.8C:0.2Sn at temperatures from 13501 to 15001C. J ournal

Tribological behaviors and the relevant mechanism of a highly pure polycrystalline bulk Ti 3 AlC 2 sliding dryly against a low carbon steel disk were investigated. The tribological tests were carried out using a block-on-disk type high-speed friction tester, at the sliding speeds of 20-60 m/s under a normal pressure of 0.8 MPa. The results showed that the friction coefficient is as low as 0.1$0.14 and the wear rate of Ti 3 AlC 2 is only (2.3-2.5) Â 10 )6 mm 3 /Nm in the sliding speed range of 20-60 m/s. Such unusual friction and wear properties were confirmed to be dependant dominantly upon the presence of a frictional oxide film consisting of amorphous Ti, Al, and Fe oxides on the friction surfaces. The oxide film is in a fused state during the sliding friction at a fused temperature of 238-324°C, so it takes a significant self-lubricating effect.

A nearly pure, dense Ti3Al0.8Sn0.4C2 solid solution bulk has been prepared by two‐time hot‐pressing sintering a purity Ti3Al0.8Sn0.4C2 powders at 1450°C with 30 MPa for 30 min in Ar atmosphere. The Ti3Al0.8Sn0.4C2 powders have been synthesized by sintering a mixture of Ti, Al, Sn, and TiC powders with a molar ratio of 1:0.8:0.4:1.85 at 1450°C for 5 min. The Vickers microhardness and flexural strength of the Ti3Al0.8Sn0.4C2 have been measured to be 3.51 GPa and 620 MPa, respectively. Buckling and kinking of the layered structure as well as grain delamination crack deflection have been extensively observed around indentations and on the fracture surfaces. The tribological behaviors have been investigated by dry sliding a low‐carbon steel disk. Ti3Al0.8Sn0.4C2 bulk has a friction coefficient of 0.3–0.48 and a very low wear rate of 0.4–4.3 × 10−6 mm3/Nm for the test conditions. These tribological properties are attributed to the presence of a compact self‐generating film, which covers uniformly over the friction surface of Ti3Al0.8Sn0.4C2.

Highly pure and dense Ti 2 AlC and Ti 2 AlSn 0.2 C bulks were prepared by hot pressing with molar ratios of 1:1.1:0.9 and 1:0.9:0.2:0.85, respectively, at 1450 ℃ for 30 min with 28 MPa in Ar atmosphere. The phase compositions were investigated by X-ray diffraction (XRD); the surface morphology and topography of the crystal grains were also analyzed by scanning electron microscopy (SEM).