A novel approach to modelling the effect of compaction parameters on mode I fracture toughness of green iron (Fe) powder compact

Abstract

This research introduces a novel and efficient method to model mode I fracture toughness in green iron (Fe) powder compacts. Departing from the traditional complex and computationally intensive methods, we propose an innovative approach by integrating Taguchi design of experiments (DOE) and statistical regression modelling. Several complex mathematical models and finite element modelling software have been used to study the responses of the mode I fracture toughness (K_IC) and the relative density (RD) of metal powder compacts to variation in compaction pressure and/or mass of powder used. Taguchi DOE is a robust statistical and modelling tool. This tool is easier to handle than most modelling software that has been used to model the behaviour of metal iron powder compacts. We studied the effect of two processing parameters or factors (mass and compaction pressure) on the K_IC and RD of green iron powder compacts. The L₁₆ orthogonal array was chosen for the 2-factor and 4-level experiments. The mass of the powder varied from 8 to 11 g while the compaction pressures used were 288.9, 333.4, 377.8 and 422.3 MPa. The results showed that the best combination of the two factors that gave optimal RD of 84% was 9 g of powder and 422.3 MPa compaction pressure. While the optimal K_IC was attained with 10 g of powder compacted at 422.3 MPa. Although, the ANOVA showed that both processing factors significantly affected the K_IC and RD of iron powder compacts, the compaction pressure has a greater effect on both, contributing about 90% and 61% respectively. The confirmatory test showed that Taguchi DOE could reliably be used to predict the effect of the mass of powder and compaction pressure on K_IC and RD of the iron powder compact.