Modelling and Simulation of Al/SiCp MMCs During Hot Machining

Abstract

Metal Matrix Composites (MMCs) give higher strength and stiffness, greater wear resistance over a wide range of conditions, making them an option in replacing conventional materials for many engineering applications. These materials are difficult-to-machine due to high hardness and abrasive nature of reinforcing elements like silicon carbide, aluminum oxide, and boron carbide particles. High tool wear and pits, cavities on machined surface due to fracturing of reinforcements puts certain constraints on MMCs for experimentation. Similarly, the experimental or analytical approaches are not able to explore the behavior of MMCs during machining due to the complex deformation and interactions with particles, matrix and tool. The numerical approach is very important tool to simulate the machining process of MMCs in which plastic deformations, modelling the plasticity are involved. FEM analysis eliminates the restrictions of experimental approach such as control of large process parameters, the exhaustive material characterization and the trial-and-error approach which is expensive and time consuming procedure to determine the mechanical responses. These advantages of finite element method make this approach more popular. It has come up as the main tool of simulation of metal cutting processes to calculate stress, strain, strain-rate, temperature distributions, tool wear, cutting forces and chip formation. In this paper, an attempt is made to present a 3D oblique finite element modelling using Deform software. In Deform, FEM analysis carried out by using steps are preprocessing, simulation and post-processing of data for the established machining process. Deform 3D is a robust simulation tool that uses the finite element model to complex machining process in three dimensions. It has been used in simulations of two types of Al/SiCp/220 MMCs with 10 and 30% of SiC reinforcement particles. These materials are considered as perfectly plastic and its shape was taken as a curved model by means of coated carbide insert as a rigid body. A simulation scheme involves size and weight fraction of reinforcement, speed, feed rate, depth of cut and preheating temperature. Four levels of speed, feed rate, depth of cut and preheating temperature are chosen. Designs of experiments are done by Taguchi’s design of experiments (DOE). For four level four parameters, suitable L16 orthogonal arrays are selected. Based on design of experiments, a machining simulation and analysis are carried out using Deform 3D, software. Obtained finite element simulation results are found to be closely match within 10 to 15% variation with the experimental results during hot machining of Al/SiCp/220 metal matrix composites (MMCs).