Microstructure, Mechanical and Thermal Insulation Properties of Potassium Hexatitanate Whiskers Thermal Insulation Materials

Abstract

Potassium hexatitanate whiskers (PTW) materials have attracted much attention in thermal insulation fields. Nevertheless, the low mechanical properties limited the development and application of PTW thermal insulation materials. In this work, low density, high mechanical properties and high thermal insulation capacity of PTW thermal insulation materials can be obtained through mesocarbon microbeads (MCMB) adopted as pore-forming agent. The pyrolysis and oxidation of MCMB promoted the development of whiskers during the calcination process, rendering the increased materials porosity. The as-prepared PTW materials heat treated at 1000°C possessed low thermal conductivity of 0.043-0.035 W.m−1.K−1 from room temperature to 900°C and a low bulk density of 0.52 g.cm−3. Owing to the point of contact between whiskers with developed diameter and aspect ratio, comperssive strength of PTW materials heat treated at 900° and 1000°C was 1.92 and 2.51 MPa, respectively, maintaining high resilience rates of above 70% at 5% compressive strain. The elevated heat-treatment temperature (above 1100°C) led to the sintering between whiskers and the resultant enhanced compressive strength of higher than 4.23 MPa. The researched low density, high mechanical properties and thermal insulation PTW materials exhibit huge prospects as insulation linings in thermal insulation fields. GRAPHICAL ABSTRACT