Effect of Moisture Content and Density on Thermal Conductivity and the Diffusivity of Abrasive Agglomerates

الملخص

Aluminum oxide grinding wheels are among the most common and durable abrasive materials, boasting high hardness. They are primarily used for grinding and sharpening metals with high tensile strength, such as steel and wrought iron, and for removing burrs. As is well known, grinding wheels made of aluminum oxide were used in the early twentieth century (around 1900–1910) as a manufactured and durable alternative to natural abrasives such as sandpaper. These wheels were developed to meet the need for grinding metals with high tensile strength, such as steel and iron, providing fast cutting and high durability in industrial processes. When grinding temperatures rise, the moisture absorbed by the grinding wheels turns to steam, generating internal pressure that can lead to wheel cracking or a decrease in the strength of the bond (glass bond), thus accelerating wheel wear. However, this also has a positive effect, as the moisture (water) within the wheel pores increases the overall heat capacity of the body (wheel + water) because water has a very high heat capacity, temporarily reducing the temperature rise of the grinding surface. This work aims to highlight two material properties by studying this effect on the thermal and physical performance of abrasive materials using modulated differential scanning calorimetry (MDSC) 2920 to determine specific heat capacity and the flash diffusion method to evaluate thermal conductivity derived from the quantified thermal diffusion.