Hardening (computing)

Plasticity

Slip (aerodynamics)

Metallurgy

Materials science

Metastability

Layer (electronics)

Adiabatic shear band

Strain hardening exponent

Thermodynamics

Physics

Organic chemistry

Alloy

Microstructure

Composite material

Diffusionless transformation

Crystallography

Chemistry

Martensite

Deformation mechanism

Strain rate

Crystal twinning

Mechanics of Materials

Compressive response of a novel Fe38·5Mn20Co20Cr15Si5Cu1.5 high entropy alloy with transformation induced plasticity made by laser powder bed fusion was studied at quasi-static, medium and high strain rates. Mechanical response and variation in work hardening rate with strain rate were correlated with γ (f.c.c.) → ε (h.c.p.) martensitic transformation, subsequent phase evolution and adiabatic heating. A strong near basal {0 0 0 1} texture observed in the transformed ε (h.c.p.) phase after deformation was correlated with the initial texture, γ (f.c.c.) → ε (h.c.p.) transformation orientation relationship, as well as the activated deformation mechanisms in ε (h.c.p.) phase. The initial c/a ratio of 1.612 for the ε (h.c.p.) phase evolved with deformation and this was quantified to understand the propensity of non-basal <c+a> slip activation. Metastable γ (f.c.c.) dominant microstructure in the as-built alloy enabled excellent hardening via γ (f.c.c.) → ε (h.c.p.) transformation accompanied by activation of non-basal <c+a> slip and twinning. Experimental results were correlated with existing empirical constitutive models such as Johnson-Cook, Modified Zerilli-Armstrong, Khan-Huang-Liang and Khan-Liu; the Khan-Liu model evidenced the best correlation with experimental results.

Strain rate sensitive microstructural evolution in a TRIP assisted high entropy alloy: Experiments, microstructure and modeling