Investigations for dimensional accuracy of AMC prepared by using Nylon6-Al-Al2O3 reinforced FDM filament in investment casting

Abstract

Purpose This paper aims to investigate the dimensional accuracy of aluminium (Al) matrix composites (AMCs) prepared by using an alternative reinforced fused deposition modeling (FDM)-based sacrificial patterns in investment casting (IC) process. Further in this work, a barrel finishing (BF) process has been introduced as an intermediate step for the improvement of surface finish of sacrificial patterns and to study the effect of BF process parameters on dimensional features of the casted AMCs. In the present research, an effort has been made to ascertain the capability/producibility of the proposed route for obtaining good geometrical tolerances. Design/methodology/approach Alternative reinforced FDM filaments were developed using single screw extruder whose melt flow index was matched with the commercial acrylonitrile–butadiene–styrene filament. IC sacrificial patterns, fabricated on existing FDM system without making any change in its hardware/software, were barrel finished for improving the surface finish. The effect of FDM, BF and IC process parameters, namely, type of filament, volume of CAD-based cubical pattern, pattern density, BF time, BF media weight and numbers of IC slurry layers, was studied using Taguchi L18 OA approach. Findings Dimensional accuracy of casted AMCs developed was optimized successfully using Taguchi L18 orthogonal array. Optical microscopic analysis made on the castings highlighted the presence of Al2O3 particles which will result into the improvement of mechanical and tribological properties. International tolerance grade of cast AMCs was calculated and found acceptable as per ISO standard UNI-EN-20286-I (1995). Further, there are strong possibilities of process to be under statistical control at proposed settings. Originality/value The paper describes a new route for the development of AMC. The effect of FDM, BF and IC process parameters on dimensional accuracy of AMCs developed is also highlighted in the present research.