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Fatigue of Electroformed Nickel

  • H. Jahed
  • M. Noban
Technical Article---Peer-Reviewed
  • 147 Downloads

Abstract

A 2–3 mm nickel mould, manufactured solely by electroforming, showed early cracking under thermal load cycles. Possible causes were attributed to material, design, or service deficiencies. The root cause of early fracture has been investigated thoroughly and is reported here. Monotonic and cyclic properties of electroformed nickel have been obtained at room and elevated temperature. Fatigue mechanisms were identified and compared to pure nickel. Finite element modeling of the mould under thermal cycles enabled the study of material, design, and in-service applications of the mould. It was found that over constraining the mould, while it was in service, caused excessive thermal stresses which accelerated crack initiation and propagation. Remedies to avoid failure are proposed.

Keywords

Electroformed nickel Thermal cycle Fatigue failure Thermal stress 

Notes

Acknowledgment

The authors acknowledge the help of Dr. S. Winkler with the microstructure studies.

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Copyright information

© ASM International 2009

Authors and Affiliations

  1. 1.Mechanical & Mechatronics Engineering DepartmentUniversity of WaterlooWaterlooCanada

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