Low cycle fatigue lifetime and deformation behaviour prediction of nickel-based single crystal superalloy considering thickness debit effect

•The LCF performances with thickness debit effect of nickel-based single crystal superalloy DD6 with [001] orientation are investigated.•Based on SEM observation, the formation mechanism of thickness debit effect and the damage mechanism under LCF loads are revealed.•A thickness-sensitive LCF damage model of nickel-based single crystal superalloy DD6 is proposed.•The stress-controlled LCF deformation behaviours including the whole-lifetime ratcheting behaviours are well predicted.