Journal of Materials Research and Technology (Jan 2021)
Experimental analysis and parametric optimization of drilling process for ferrous clay composite using GRA-PCA approach
Abstract
The use of materials mixture with non-metallic ingredients composed by powder metallurgy (PM) are getting increased attention in many industries. The newly developed composite material is mainly applied to the structural parts in the many industries. PM parts machining is still a challenge and known as difficult-to-cut metals for manufacturers because of the many factors mainly porosity, Nano particles and complex microstructure. In this work, the mechanical properties like density and porosity along with the machinability in drilling of a newly developed sintered powder metallurgy (P/M) components having Nano-particles of bentonite clay as machinability enhancer is evaluated by a standard twist drill. The impact of this paper aims to reveal the key cutting phenomena i.e. generation of thrust forces, quality of surface roughness, and new insight into the machining mechanism of sintered material. The parameters involved in the machinability study are as speed, feed rate and Nano-particles of bentonite clay for controlling the parametric variables on the response parameters. The speed has the major (95%) effect on the thrust force where the clay percentage has the major (84%) effect on the surface roughness. The less thrust force and low surface roughness have been achieved at 5% clay with 910 rpm and 1% clay with 2265 rpm, respectively. Further, the hybrid grey relational analysis along with principal component analysis (GRA-PCA) has been carried out to find the optimum condition. The less thrust force (Ft) and low surface roughness (Ra) has been found at 1% clay and 910 rpm. The confirmation of optimal process parameters has been made with overall evaluation criteria (OEC) and found the same optimum condition. The X-ray diffraction despises homogeneous mixture of clay in ferrous clay composite. The SEM analysis exposed the presence of clay particles and plastically deformed area during drilling of ferrous clay composite. Thus, this analysis show that the 1% of Nano-particles of bentonite clay is helpful as porosity fillers or machinability enhancer at low speed and within acceptable mechanical properties.
