Investigation on mechanical properties of ZTA+ Cr 3 C 2  + Ni reinforced EN31 steel-based composite material: Micromechanical finite-element analysis

Abstract

The present investigation deals with the development of EN31 steel-based metal matrix composite material under the ultrasonic vibration effect by providing 20 kHz frequency. In the process of the development of composite material, primary and secondary reinforcement has been taken as zirconia toughened alumina (ZTA) and Cr₃C₂ (chromium (II) carbide), respectively. The Ni has also been taken as dissolving reinforcement material and its weight percentage (wt.%) is kept constant at 2.5%. The variation in ZTA weight percentage was selected between 1.25% and 10%. Furthermore, the weight percentage of Cr₃C₂ has been kept constant (2.5 wt.%) throughout the development of different composite samples. The microstructural investigation indicated the fair distribution of reinforcement particles up to the 3.75 wt.% of ZTA, developed with the ultrasonic vibration effect. Furthermore, the addition of 2.5 wt.% of nickel in the EN31 steel has improved the wettability of ZTA and Cr₃C₂ particles. The best values of hardness (254.22 BHN) and tensile strength (892.15 MPa) were achieved with the composition of EN31/3.75 wt.% ZTA/2.5 wt.% Cr₃C₂/2.5 wt.% Ni composite material sample. Furthermore, the tensile strength and hardness of EN31 steel matrix material were improved by about 45.065% and 100.36% respectively. The addition of ZTA and Cr₃C₂ decreases the ductility of EN31 steel matrix material. The addition of 2.5wt.% Ni powder with ZTA+ Cr₃C₂ improved the ductility of EN31 steel. The results revealed that the mechanical properties (tensile strength, hardness, and ductility) of the developed composite material were further improved after performing the heat treatment process. Furthermore, an approach has been made to investigate the micro-mechanical deformation of EN31/3.75 wt.% ZTA/2.5 wt.% Cr₃C₂ metal matrix composite representative volume element (size: 225 × 225 × 225 nm) with finite-element analysis (FEA). The maximum stress (895.60 MPa) is generated at matrix–particle interfaces, which is the main reason for failure. The percentage difference between FEA and experimental results was less than 10%.