Sustainable manufacturing of ultra-precision machining of titanium alloys using a magnetic field and its sustainability assessment

Titanium alloys are widely used in fabrication of certain medical products because of their superior properties. However, titanium alloys are difficult to cut, because of their low thermal conductivity and high sustainability of work hardening at elevated temperature. Therefore, machining of titanium alloys involves lots of machining difficulties especially in ultra-precision machining. On the other hand, an increase in material removal rate (MRR) always reduces surface quality, leading an infeasibility of high MRR machining of titanium alloys. In this study, a novel machining technology, a magnetic field was firstly applied into single point diamond turning (SPDT), which aims to enhance both MRR and the surface quality of machined titanium alloys without requiring complicated equipment and extra natural resources. Under the influence of a magnetic field, the surface quality of machined titanium alloys and diamond tool life in SPDT were improved significantly when machining at relatively high MRR. Furthermore, the sustainability assessment of machined products was demonstrated by product sustainability index (ProdSI), which ProdSI reflects the comprehensive views on the triple bottom line (TBL) of sustainability: economic, environmental and social dimensions. ProdSI of the machined components by SPDT in the presence of magnetic field was 2.39 higher than that by normal SPDT, suggesting an enhancement of product sustainability by the proposed machining technology. The proposed machining technology provides a solid way to increase both the production rate and the precise level of titanium alloy components for promoting sustainable ultra-precision manufacturing.