Characteristics of Microcellular Foamed Ceramic Urethane.

Ceramics are non-metallic inorganic materials fabricated from natural or high-purity raw materials through heating and cooling processes. Urethane is a three-dimensional plastic with both elasticity and chemical resistance; moreover, it is used as a rubber substitute. The use of both materials in various applications is gradually increasing. However, as ceramics and urethane have distinctly different properties, this prompted questions regarding the properties of a material that is fabricated using both materials. Therefore, we studied the characteristics of a composite material fabricated through physical foaming using a batch process. The process was conducted with gas saturation, foaming, cooling, and curing. When a specimen of 2 mm thickness was saturated in 5 MPa of CO2 for 2 h, the solubility was 6.43%; when foaming was carried out at a temperature of 150 °C in boiled glycerin, the foaming ratio, cell size, cell density, and void fraction were found to be 43.62%, 24.40 µm, 9.1 × 10⁷ cells/cm2, and 22.11%, respectively. Furthermore, the volume increased by 102.96%, color changed from dark to light gray, hardness decreased by 24%, thermal diffusivity increased by 0.046 mm2/s at 175 °C, and friction coefficient decreased to 0.203. Thus, the microcellular foamed ceramic urethane exhibits a larger volume, lighter weight, and improved thermal conductivity and friction coefficient.