Fabrication, Mechanical Properties, and Tribological Behaviors of Ti₃Al_0.8Sn_0.4C₂ Solid Solution by Two‐Time Hot‐Pressing Method

Abstract

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.

Fabrication, mechanical properties, and tribological behaviors of Ti2AlC and Ti2AlSn0.2C solid solutions

“…3(c), there exists no other impurity phase; nevertheless, Al 2 O 3 has been formed due to reaction of Al with oxygen that is present as an absorbed species at the original powder surface. A small amount of Al 2 O 3 is commonly observed in Al-containing MAX phase, like Ti 3 Al(Sn)C 2 [9,10] and Cr 2 Al(Si)C [17]. The grains of Ti 2 AlSn 0.2 C are lined up tightly as shown in Fig.…”

“…Li et al [8] measured the flexural strength of Ti 3 SiAl 0.2 C 2 to be 425 MPa, 13% above that of Ti 3 AlC 2 . In our earlier work [9,10], the microhardness and flexural strength of the Ti 3 SiAl 0.2 C 2 solid solution were measured to be 3.53 GPa and 560 MPa, respectively, and the value is 12% and 51% higher than that of Ti 3 AlC 2 . However, the exact mechanism of strengthening or weakening effect of the MAX solid solution by substitution into A site is uncertain now.…”

“…Due to the similar layered structure and similar characteristics in the same location of different elements, the study of MAX phase solid solutions likewise aroused the interest of researchers [4][5][6][7][8][9][10][11][12][13]. In the existing researches, solid solutions like (Cr 1x V x ) 2 AlC [4,5], Ti 3 Si(Al)C 2 [6][7][8], Ti 3 Al(Sn)C 2 [9][10][11][12], and Ti 2 AlC 0.5 N 0.5 [13] have been reported to possess improved flexural strength, hardness, tribological properties, thermal expansion coefficient, etc. MAX phases and their solid solutions are demonstrated to have considerable advantages of unique nanolamellar crystal structure, high strength, resistance to elevated temperature decomposition and chemical corrosion, and so on.…”

“…In recent ten years, many researches in tribological study of MAX phases like Ti 3 SiC 2 and Ti 3 AlC 2 and MAX matrix composite materials have been conducted [9,10,[18][19][20][21][22][23]. Gonzalez-Julian et al [19] consolidated the Cr 2 AlC/SiC fiber composites to evaluate the tribological properties of Cr 2 AlC, and found that the friction decreases up to 20% while the wear resistance increases up to 80% for Cr 2 AlC/10SiC composite.…”

“…Zhai et al [22] and Huang et al [23] reported that due to the oxide film with self-lubricating effect on the friction surface, Ti 3 SiC 2 and Ti 3 AlC 2 exhibit excellent tribological properties sliding against low-carbon steel. Xu et al [9] and Huang et al [10] added 0.2Sn and 0.4Sn to fabricate Ti 3 Al(Sn)C 2 solid solutions; the experimental investigation showed that micro-Vickers hardness is about 12% higher and the flexural strength is increased by 51% and 67% respectively, compared with Ti 3 AlC 2 . Moreover, Ti 3 Al(Sn)C 2 solid solutions showed excellent tribological properties during dry sliding against a low-carbon steel disk.…”