Three-dimensional Numerical Simulation of Green Metal Powder Compacts Crack Based on DPC-CZM Mixed Model

Elimination and control of green metal powder compacts cracks can guide the production of high-quality powder metallurgy parts. In this work, the modified Drucker-Prager Cap (DPC) model and the cohesive model (CZM) are combined to define the mechanical behavior. The modified DPC model is used to define the solid elements, the cohesive model is used to define the zero-thickness element. Through Brazilian disc and uniaxial compression test, the fracture performance parameters of the blank were obtained, then the Python program was programmed to insert zero-thickness cohesive element in the solid element. The tensile and shear crack of green metal powder compacts under external load are simulated and compared with the experimental results. The results show that combining the exponential cohesive zone constitutive model with the DPC model can be used to describe the change of crack damage zone more accurately, which was also able to reflect the green compacts damage process and crack propagation associated with the zero-thickness elements. © 2020, Materials Review Magazine. All right reserved.