Dr. Zhichao (Charlie) Li
Zhichao (Charlie) Li is a principal engineer at Dante Software, located in Cleveland, Ohio. Dr. Li received his bachelor and master degrees on materials engineering from the Harbin Institute of Technology in China, and his doctoral degree from Wright State University. He continued his studies and earned in 2012 his MBA from Baldwin Wallace University. Dr. Liâ€™s areas of expertise are design, innovation and optimization for heat treatment processes, materials characterization, finite element modeling, etc. Liâ€™s current focus at Dante is on heat treatment software development, technical support to Dante users, and new market development. (Bio last updated 2014-07-01 Contact Randy Stott, Managing Editor, with changes.)
Articles by Zhichao (Charlie) Li
- Innovative Induction Hardening Process with Pre-heating for Improved Fatigue Performance of Gear Component (July 2014)
Contact fatigue and bending fatigue are two main failure modes of steel gears, while surface pitting and spalling are two common contact fatigue failures -- caused by alternating subsurface shear stresses from the contact load between two gear mates. And when a gear is in service under cyclic load, concentrated bending stresses exist at the root fillet -- the main driver of bending fatigue failures. Induction hardening is becoming an increasingly popular response to these problems, due to its process consistency, reduced energy consumption, clean environment and improved product quality -- but not without issues of its own (irregular residual stresses and bending fatigue). Thus a new approach is proposed here that flexibly controls the magnitude of residual stress in the regions of root fillet and tooth flank by pre-heating prior to induction hardening. Using an external spur gear made of AISI 4340 as an example, this new concept/process is demonstrated using finite element modeling and DANTE commercial software.