Self-lubricating performance of a grinding wheel filled with CNTs@T304 nano-capsules

Abstract

This paper introduces a new grinding wheel which lubricates the grinding area directly. This is achieved by filling a resin grinding wheel with nano-capsules comprised of carbon nanotubes (CNTs) and di-n-butyl phosphite (T304) (CNTs@T304). The CNTs@T304 nano-capsules filled grinding wheel reduces the grinding force, lowers the grinding temperature, and improves the workpiece surface quality. The T304 lubricant is first filled into the CNT cavity to prepare nano-capsules, which exhibit better friction and wear quality than CNTs. Then the paper analyzes the configuration of the nano-capsules in the grinding wheel, together with the investigation of how the filling content impacts the mechanical properties. Additionally, the effects of nano-capsule filling content and grinding parameters on grinding force, grinding temperature, grinding ratio, as well as workpiece surface roughness are studied and the self-lubricating mechanism of the nano-capsules is assessed. According to the experimental results, nano-capsules maintain stable under thermal condition and resist the curing temperature. Moreover, the tensile strength and hardness exhibited by the grinding wheel still meet the application requirements at a filling content <16 wt%. Compared with the grinding wheel without fillers, the nano-capsule filled wheel exhibits superior grinding performance, with a 33 % reduction in the grinding force. Also, the grinding temperature is 28 % lower, there is a 30 % improvement in the grinding ratio, and the workpiece surface quality increases by 35 % under the same conditions. The T304 in the nano-capsules is continually released onto the grinding interface with the wear of the wheel in the grinding process, which forms a self-lubricating layer along with the friction products of the CNTs. This exerts an outstanding anti-friction and anti-wear effect, thereby improving the grinding performance.