Experimental investigation into machining of hastelloy C-276 during different cooling environments

Abstract

Hastelloy has been recommended as difficult to machine material because of its less thermal conductivity and specific heat capacity, despite that it is having numerous applications in aerospace, nuclear reactor and petroleum industries due its excellent strength as well as heat carrying capacity. Since, the machining of this material is challenging and hence there is a need to conduct the experiment and finding the best machining parameters. Traditionally the flood lubrication practiced for machining operation leads to several negative effects due to the high discharge of metal working fluids and also adds machining cost along with ecological imbalance and health hazards to workers. Therefore to eliminate the undesirable effects of wet cooling the dry machining has been preferred neglecting the aforementioned phenomenon. However this approach faces challenges at higher levels of process parameters causing quick tool damage and lower surface quality. Hence to avoid the undesired phenomenon of aforementioned cases the MQL and other cooling techniques have been utilized to bridge the gap between traditional cooling and dry machining system. In present investigations the role of varying input parameters on machining performance has been evaluated considering surface roughness, temperature and chip reduction coefficient during dry, flood and MQL conditions. The experimental results along with ANOVA analysis expressed that doc and cooling environment have major influence on surface finish, whereas the cutting speed, cooling environment and doc have remarkable impression on temperature, furthermore the feed rate has dominant impression on chip reduction coefficient and shear angle.