Self-healing of indentation damage in Ti₂AlC MAX phase ceramics

Although the crack-healing capacity of Ti₂AlC ceramics has been sufficiently studied, the ability of Ti₂AlC to self-heal large-scale damage, such as foreign object damage (FOD), remains unknown. This paper investigates the self-healing ability of Ti₂AlC ceramics with large-scale damage (∼1000 μm in diameter)....

On the formation mechanisms and properties of MAX phases: A review

MAX phases are a family of ternary carbide or nitride ceramics possessing a layered crystal structure and, due to their chemical bonds having a mixed covalent-ionic-metallic nature, have unique properties combining those of metals and ceramics. In this review, the formation mechanisms of MAX phases from elemental and compound powders are...

Butane Dry Reforming Catalyzed by Cobalt Oxide Supported on Ti₂AlC MAX Phase

MAX (M_n+1AX_n) phases are layered carbides or nitrides with a high thermal and mechanical bulk stability. Recently, it was shown that their surface structure can be modified to form a thin non-stoichiometric oxide layer, which can catalyze the oxidative dehydrogenation of butane. Here, the use of a Ti₂AlC MAX...

Point contact abrasive wear behavior of MAX phase materials

The room temperature abrasive wear behavior of three selected MAX phases, Ti₃SiC₂, solution strengthened Ti_2.7Zr_0.3SiC₂ and Cr₂AlC, is investigated by low velocity scratch testing using a diamond conical indentor with a final radius of 100 μm and a cone angle of 120° and...

Synthesis, crystal structure, microstructure and mechanical properties of (Ti_1-xZr_x)₃SiC₂ MAX phase solid solutions

Almost pure (Ti_1-xZr_x)₃SiC₂ MAX phase solid solutions with x ranging up to 0.17 were synthesized at temperatures in the range of 1450–1750 °C with reactive Spark Plasma Sintering (SPS). The zirconium partially replaces the M-element titanium of the Ti₃SiC₂ MAX phase up to x...

Low-temperature oxidation-induced crack healing in Ti₂Al_0.5Sn_0.5C–Al₂O₃ composites

The oxidation-induced crack healing of an Al₂O₃ composite loaded with various volume fractions of Ti₂Al_0.5Sn_0.5C repair filler particles was investigated by annealing in air at a relatively low temperature of 700°C. After annealing a composite with 20 vol.% repair fillers (with a particle...

Work of adhesion of interfaces between M₂AlC (M = Ti, V, Cr) MAX phases and α-Al₂O₃

A fast and generic scheme is proposed to calculate the work of adhesion between two different materials or the cohesive energy between two crystal planes in a material. These calculations make use of the regular solution theory. This theory is extended to describe chemical interactions between atoms at either side of an interface. The so...

Autonomous high-temperature healing of surface cracks in Al₂O₃ containing Ti₂AlC particles

In this work, the oxidation-induced crack healing of Al₂O₃ containing 20 vol.% of Ti₂AlC MAX phase inclusions as healing particles was studied. The oxidation kinetics of the Ti₂AlC particles having an average diameter of about 10 μm was studied via thermogravimetry and/or differential thermal...

Toughening mechanisms in nanolayered MAX phase ceramics-a review

Advanced engineering and functional ceramics are sensitive to damage cracks, which delay the wide applications of these materials in various fields. Ceramic composites with enhanced fracture toughness may trigger a paradigm for design and application of the brittle components. This paper reviews the toughening mechanisms for the nanolayered...

Synthesis and oxidation behaviour of Ta-Al-C MAX phases

MAX-phase materials, a class of ternary carbides and nitrides that combine favorable properties of metals (conductivity and toughness) and ceramics (high temperature strength) have been shown to autonomously heal micro-cracks by high temperature oxidation. The investigation of Ta and Al containing MAX phases (Ta2AlC & Ta4AlC3) could render self...

Demonstrating the self-healing behaviour of some selected ceramics under combustion chamber conditions

Closure of surface cracks by self-healing of conventional and MAX phase ceramics under realistic turbulent combustion chamber conditions is presented. Three ceramics namely; Al₂O₃, Ti₂AlC and Cr₂AlC are investigated. Healing was achieved in Al₂O₃ by even dispersion of TiC...

A conceptual study into the potential of MAX-phase ceramics for self-healing of crack damage

The reduction of maintenance and replacement work costs is an important driving force in the development of high temperature materials (T>800 °C) that can autonomously heal damage as a result of local cracks. In recent years some potential routes involving the addition of sacrificial particles have been identified, yet these systems have the...

Self-healing of yttrium-doped CR2ALC MAX phase coatings deposited by hipims

Self-healing materials allow for a design concept based on damage management where damage that is inflicted during operation can be healed autonomously. It has been shown that the Mn+1AXn phases Ti3AlC2, Ti2AlC and Cr2AlC exhibit autonomous self-healing behaviour. Cracks are filled and hence healed by oxidation products of the M and A elements...

A conceptual study into the potential of max-phase ceramics for self-healing of crack damage

The reduction of maintenance and replacement work costs is an important driving force in the development of high temperature materials (T>800 °C) that can autonomously heal damage as a result of local cracks. In recent years some potential routes involving the addition of sacrificial particles have been identified, yet these systems have the...

Multiple crack-healing and strenght recovery in MAX phase ceramics (abstract)

Electrochemical healing of MAX phase ceramics (abstract)