Modeling segmentation cracking of a brittle coating due to underneath periodic eigenstrains

• The formation mechanism for a segmented Cr coating was investigated.
• A model was proposed for segmentation cracking initiation and extension.
• The dependence of dimensionless variables on the stress field and SIFs was assessed.
• The spacing of formed segmentation cracks can be tuned.

The formation mechanism for a segmented Cr coating by the hybrid technique of laser pre-quenching steel substrate plus post-electroplating was investigated. The discrete laser quenched zones (LQZs) were modeled as multiple inclusions with prescribed eigenstrains. The stress field was determined to account for the onset of segmentation cracking. Also addressed was segmentation crack growth through the evaluation of the stress intensity factor (SIF). The computations were implemented by using the finite element (FE) method. The dependence of a wide range of dimensionless variables of interest on both the stress field and SIF was assessed through a detailed parametric study.