Researchers Develop New Technique for Fabricating Large-Scale Metal Components

Strategic Insights -

Researchers from the PSG College of Technology have made significant progress in the field of mechanical engineering by developing a new technique for fabricating large-scale metal components. This technique, known as cold metal transfer (CMT)-based wire arc additive manufacturing (WAAM), allows for the creation of complex metal components with high deposition rates, cost efficiency, and design flexibility. The research team successfully fabricated a functionally graded material (FGM) comprising SS321 and Hastelloy C-276 using CMT-WAAM.

Key Takeaways:

  • The new technique, CMT-WAAM, has emerged as a promising method for fabricating large-scale and complex metal components due to its high deposition rate, cost efficiency, and design flexibility.
  • The FGM fabricated using CMT-WAAM exhibited a smooth compositional gradient with minimal segregation, ensuring strong metallurgical bonding.
  • Microhardness tests revealed that the microhardness gradually declined with build height due to thermal accumulation, ranging from 220 to 197 HV in SS321 and 272 to 236 HV in Hastelloy C-276.
  • Interface tensile specimens exhibited a UTS of 675 MPa, YS of 436.7 MPa, and an elongation of 48.22%.
  • Fractures in vertical specimens occurred near the SS321 side, confirming it as the weaker zone.
  • SEM fractography revealed ductile failure characterized by micro-voids coalescence and fine dimples.
  • The research concluded that CMT-WAAM proves effective for fabricating FGMs with smooth transitions and dependable mechanical integrity.
  • The team received financial support from the Department of Robotics and Automation Engineering.

Statistics:

  • The microhardness of SS321 ranged from 220 to 197 HV.
  • The microhardness of Hastelloy C-276 ranged from 272 to 236 HV.
  • The UTS of the interface tensile specimens was 675 MPa.
  • The YS of the interface tensile specimens was 436.7 MPa.
  • The elongation of the interface tensile specimens was 48.22%.

Sources:

  • "Microstructural and Mechanical Characteristics of Cmt-waam Fabricated Ss321 and Hastelloy C-276 Functionally Graded Material." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering, 2025.
  • Sage Publications Ltd, 1 Olivers Yard, 55 City Road, London EC1Y 1SP, England.
  • Dhanabalakrishnan Mariappan, PSG College of Technology, Dept Robot & Automat Engn, Coimbatore 641004, Tamil Nadu, India.