ICAMS / Interdisciplinary Centre for Advanced Materials Simulation

Events

Atomistically informed full-field simulation of tempered martensite: Quenching, tempering and mechanical characterization

Date: 20.09.2017
Time: 11:00
Place: EUROMAT 2017, Thessaloniki, Greece

Ingo Steinbach

A scale bridging modelling and simulation strategy of virtual production and virtual testing is presented which starts with parametrization of continuum constitutive relaions by quantum mechanical calculations at the atomistic scale. These models are integrated into a full-field framework at the scale of microstructures in technical materials. The phase-field method is employed to simulate the microstructure evolution during processing: virtual production. Finally micromechanical simulations of deformation and damage evolution till catastrophic failure are performed utilizing the full information about the microstructure, composition and residual stresses resulting from the production route: virtual testing. The approach is applied to tempered martensite, describing the evolution of the microstructure under quenching, tempering and testing. The quenching simulation reproduces the martensite transformation under consideration of the Kurdjumov - Sachs relationship. Based on these results, tempering is simulated. Diffusion is enabled at elevated temperatures and cementite carbides are nucleated, which decreases carbon composition in the martensite, which also decreases the tetragonal distortion. A virtual tension test provides then information about strain hardening, damage as well as the macroscopic response of the material to the loading. Different microstructures, as resulting from different alloy composition and different tempering conditions are compared regarding their mechanical performance.

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