Retificação da liga Ti-6Al-4V, com fluido de corte contendo partículas de grafeno

Abstract

Machining of titanium alloys by conventional processes has always been a concern topic of researchers and practitioners from metal-working industry. So, many works related to these processes have been developed to improve their machinability and to reduce manufacturing costs. However, little information has been reported in the literature about studies with regard the machinability of titanium alloys employing abrasive processes, specially grinding. The high cost of the material and the lack of titanium components that need to be ground are some reasons for this. In addition, these alloys have low thermal conductivity, which impairs use of conventional abrasive tools, because it increases the probability of occurrence of thermal damages. Into this context, it is important to find appropriated lubri-coolant conditions for efficient grinding of titanium and its alloys. The grinding parameters varied were: radial depth of cut (ae) of 10 μm and 20 μm, 2 and 3 passes and also the cutting fluid delivery technique (conventional one and the minimum quantity lubrication (MQL). Graphene nanoplatelets dispersed in the cutting fluid were also tested via MQL technique. The cutting fluid employed was the vegetable-based synthetic type for all techniques employed. Output variables were the surface roughness, the microhardness and the consumed electrical power. Images of machined surfaces and of the wheel were also obtained and analyzed. The results showed that addition of the graphene particles on the cutting fluid can improve the process performance, leading to improvement of finishing, lower variation in microhardness and lower electric power required in the grinding wheel motor, when the highest radial depth of cut was employed. Also, it was observed that the strategy of using 2 or 3 passes during grinding did not show significant effect on finishing on the conditions investigated. No visual presence of burning was observed on the machined surfaces under the conditions investigated.