Microstructure study of the hardening mechanism of Cr-Ni alloy deposits after flame heating for a few seconds

作者：Huang Ching An^*; Lin Che Kuan; Chiou Wen An; Hsu Fu Yung

来源：Surface and Coatings Technology, 2011, 206(2-3): 325-329.

DOI：10.1016/j.surfcoat.2011.07.024

• Cr-Ni alloy deposit
• Trivalent chromium ions
• Hardness
• Microstructure

Cr-Ni alloy deposits with different chemical compositions could be obtained from a bath with trivalent Cr and divalent Ni ions. With a plating current density above 20 A dm(-2), amorphous Cr-rich alloy deposits were obtained, and crystalline Ni-rich deposits were achieved with an electroplating current density lower than 15 A dm(-2). The hardness of the Ni-rich deposit decreased gradually with increasing flame-heating time. On the contrary, the hardness of Cr-rich alloy deposit could be significantly increased from 550 Hv to 1450 Hv after flame heating for 3 s. The results of a microstructure study show that the precipitation of nano-sized carbon-related particles, possibly diamond-like particles, could be the main hardening mechanism of flame-heated Cr-rich alloy deposit. These particles have particularly high hardness values, and they distort the nearby Cr-rich lattice, which leads to obvious strain fields in the flame-hardened Cr-rich alloy deposits.

• 出版日期2011-10-25
• 单位长春大学