Anneal-Hardening Behavior of Cr-Fe-C Alloy Deposits Prepared in a Cr3+-Based Bath with Fe2+ Ions

Ching An Huang; Jhih You Chen; Hai Wang; Po Liang Lai

doi:10.3390/ma10121392

Anneal-Hardening Behavior of Cr-Fe-C Alloy Deposits Prepared in a Cr³⁺-Based Bath with Fe²⁺ Ions

Materials (Basel). 2017 Dec 5;10(12):1392. doi: 10.3390/ma10121392.

Authors

Ching An Huang^{1

2

3}, Jhih You Chen⁴, Hai Wang⁵, Po Liang Lai⁶

Affiliations

¹ Department of Mechanical Engineering, Chang Gung University, Taoyuan 333, Taiwan. gfehu@mail.cgu.edu.tw.
² Department of Mechanical Engineering, Ming Chi University of Technology, New Taipei 243, Taiwan. gfehu@mail.cgu.edu.tw.
³ Bone and Joint Research Center, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan. gfehu@mail.cgu.edu.tw.
⁴ Department of Mechanical Engineering, Chang Gung University, Taoyuan 333, Taiwan. d0322001@cgu.edu.tw.
⁵ Department of Mechanical Engineering, Ming Chi University of Technology, New Taipei 243, Taiwan. whai@mail.mcut.edu.tw.
⁶ Bone and Joint Research Center, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan. polianglai@gmail.com.

Abstract

Cr-Fe-C alloy deposits were successfully prepared on high-carbon tool steel in a Cr³⁺-based electroplating bath containing Fe²⁺ ions and suitable complex agents. A Cr-based alloy deposit was obtained with an electroplating current density higher than 25 Adm^-2, and a Fe-based alloy deposit was obtained using a current density of 20 Adm^-2. Following electroplating, these alloy deposited specimens were annealed via rapid thermal annealing (RTA) at 500 °C for different periods up to 30 s. The experimental results show that Cr- and Fe-based alloy deposits could be significantly hardened after RTA at 500 °C for a few seconds. The maximum hardness was that of the Cr-Fe-C alloy deposit annealed at 500 °C for 10 s. The maximum hardness of 1205 Hv was detected from the annealed Cr-based alloy deposit prepared with 30 ASD. The hardening mechanism of annealed Cr- and Fe-based alloy deposits is attributed to the precipitation of C-related membranes. The hardness values of the annealed Cr- and Fe-based alloy deposits increase with the increasing degree of crystallization of the C-related membranes.

Keywords: annealing; hardening mechanism; microstructure; trivalent Cr electroplating.