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Ti 3 AlC 2 ceramic exhibits potential in Ag-based composite electrical contact materials, but its interface characteristic with Ag matrix remains unexplored. In this work, sessile drop experiment is carried out to investigate the high-temperature wetting behavior of molten Ag with Ti 3 AlC 2. Stable Ti 3 AlC 2 is hardly wetted by molten Ag below 1000 °C(contact angle of 148.5°), but the wettability of Ag/Ti 3 AlC 2 improves with the increasing temperature(final 14° at ∼1130 °C). In contrast, the Ti 3 C 2, a MXene with Al layer removed from its parent Ti 3 AlC 2 , exhibits inferior wettability with Ag(final 56.5° at ∼1130 °C). Wetting mechanism of Ag/Ti 3 AlC 2 is proposed on the basis of the interfacial structure and chemical composition. Increasing temperature accelerates dissociation of Ti 3 AlC 2 , and outward-escaping Al reacts with Ag to form interface layer with a composition of Ag 4.86 Ti 8.66 AlC 7.59 , Ag also diffuses along Ti 3 AlC 2 grain boundaries and forms gradient reactive products(Ag–Ti–Al–C), which promotes their wettability. Finally comprehensive properties of Ag/Ti 3 AlC 2 and Ag/Ti 3 C 2 are compared. Al–Ag interdiffusion slightly decreases the electrical conductivity of Ag/Ti 3 AlC 2 bulk material, but strengthen the interface bonding of composite and promote the viscosity of the molten pool, leading to the superior mechanical and anti-arc erosion properties. Absence of Al–Ag interdiffusion does remarkably improve the electrical conductivity of Ag/Ti 3 C 2 bulk materials, but lack of Al layer damages the mechanical core and wettability with Ag, resulting in a drastic decrease of anti-arco erosion property. [ABSTRACT FROM AUTHOR]

Ti 3 AlC 2 ceramic-reinforced Ag matrix composites exhibit superior electrical contact performance. However, the arc corrosion mechanism of the Ti 3 AlC 2 reinforcing phase has not been clarified; in particular, the intrinsic relationship between the microstructure and mechanical properties needs to be further explored. In this work, by combining micro/nano-indentation, microstructural and chemical composition analysis, COMSOL simulation, and accelerated aging experiments, the relationship among phase transition, microstructural evolution, and macro/micro/nano-mechanical property changes were compared and analyzed. The cycles of arc discharge produced heat accumulation, which was transmitted from the contact surface to the interior in a gradient (divided into Areas α , β , γ). Changes in the structural dissociation, oxidation, and interfacial bonding of Ti 3 AlC 2 with the Ag matrix resulted in different micro/nano-mechanical properties in these areas in terms of micro-hardness, nano-hardness, modulus, and elastic-plasticity. These findings demonstrate the key role of the phase and microstructural evolution of Ti 3 AlC 2 on the mechanical properties of such composites while also providing a mechanical theoretical basis for future structural design and interfacial optimization of eco-friendly Ti 3 AlC 2 -reinforcing phases in Ag matrix composites. [ABSTRACT FROM AUTHOR]

A serious problem with integrated masonry linings ladle was that the ladle wall bricks were difficult to be partially replaced. Thus, the service life of the ladle was determined by the properties of ladle wall bricks. In this study, the new generation of MgO–Al 2 O 3 –C bricks with bauxite aggregates was tested in a ladle lining of an integrated steel ladle for 103 cycles, and the corroded microstructure of the used brick was investigated. A multilayered structure of bauxite aggregates could be observed in the used brick, which inhibited the slag penetration along the boundary of the magnesia aggregates and reduced the degree of the aggregates fall off from the used bricks. Besides, during the process of slag penetration, bauxite aggregates could melt into the slag, which increased the viscosity of the slag and weakened the penetration ability of the slag. The MgO–Al 2 O 3 –C bricks with bauxite addition could improve the service life of the ladle to a certain extent. [ABSTRACT FROM AUTHOR]