Transformation-induced plasticity (TRIP) in ductile iron and resultant exceptional strength-plasticity synergy

This study produces a Ni-containing ductile iron with a matrix consisting of lamellar alpha and gamma phases, along with nanoscale Mg6Si7Ni16 phases. The interface of fine alpha and gamma phases and the nanoscale Mg6Si7Ni16 phases impede dislocation mobility, contributing to high yield strength. During the tensile test, the transformation-induced plasticity (TRIP) phenomenon is etected because Ni addition effectively endows appropriate carbon concentration in gamma phase of ductile iron. The TRIP effect significantly augments the strain-hardening capacity of ductile iron, resulting in an excellent plasticity with an elongation of similar to 21 % and a considerable ultimate tensile strength of similar to 900 MPa. Consequently, the ductile iron achieves an exceptional strength-plasticity synergy, characterized by the product of tensile strength and elongation (PSE) of 19 GPa%.