Prediction of SLM-NiTi transition temperatures based on improved Levenberg–Marquardt algorithm

Abstract

In this study, we have obtained the corresponding relationship between SLM-NiTi alloy transition temperatures and energy density, and realized the accurate prediction and inverse prediction of SLM process parameters and NiTi alloy transition temperatures. And we verify the accuracy of the prediction model through DSC, XRD and SEM. Secondly, B19′NiTi and B2NiTi are successfully obtained through the prediction model. Finally, a composite gradient NiTi is established based on the idea of rigid-flexible coupling, which successfully achieved the simultaneous improvement of the strength and toughness of the SLM-NiTi alloy. The compressive fracture strength reached 2668 MPa, and the fracture strain reached 55.51%.

Keywords

• Selective laser melting
• NiTi shape memory alloys
• Additive manufacturing
• Levenberg–Marquardt algorithm
• Transition temperatures