Microstructure, Thermal Insulation, and High-Temperature Mechanical Properties of Layered Porous High Nb-TiAl Composite Sheets

Porous materials can effectively improve the thermal insulation performance of materials. Therefore, this study used pure Ti foil, pure Al powder, and pure Nb powder as raw materials. Layered porous high Nb-TiAl alloys have been prepared by vacuum hot-pressing sintering and multi-step heat treatment (low-temperature heat treatment and high-temperature heat treatment). The materials are composed of α2-Ti3Al, γ-TiAl, and Al3Nb. Holes are formed in the Al3Nb layer. The thermal insulation and tensile properties are measured at high temperature. The results show that the thermal insulation performance of the layered porous high Nb-TiAl alloy sheet is better than that of the layered high Nb-TiAl alloy (non-porous) and the traditional TiAl alloy. In this work, the materials achieved a good mechanical property-insulation performance synergy.