Tribological properties and damage behavior of brown rice based on milling process

Abstract Head rice grain has a high edible quality, while rice milling process produces lots of broken rice, mainly due to pressure and friction work. In this work, based on the structural properties of brown rice, a developed friction tester was used to analyze the tribological behavior of brown rice. Test results show that rice starch granules have a loose, polyhedral structure, which produce cracks easily and increases the abrasion of brown rice. Three kinds of brown rice show different fracture behaviors. Different friction behaviors appear with rice and milling iron kind, main rice wear mechanisms include fatigue damage, plastic deformation, adhesive wear and abrasive wear. It shows that the study provides a method to understand rice milling mechanism and has a positive influence on selection of materials and parameters for rice milling.