SUN Jie,ZHANG Xing-wei,MING Ting-yun,TAN Yong.Preparation and Properties of Rare Earth Modified Electroless Plating Coating on Titanium Alloy Surface[J],47(4):196-200
Preparation and Properties of Rare Earth Modified Electroless Plating Coating on Titanium Alloy Surface
Received:November 15, 2017  Revised:April 20, 2018
View Full Text  View/Add Comment  Download reader
DOI:10.16490/j.cnki.issn.1001-3660.2018.04.029
KeyWord:titanium alloy  elctroless plating  NiP  rare earth  heat treatment  co-deposition
           
AuthorInstitution
SUN Jie School of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang , China
ZHANG Xing-wei School of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang , China
MING Ting-yun School of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang , China
TAN Yong School of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang , China
Hits:
Download times:
Abstract:
      The work aims to prepare electroless Ni-P coating on titanium alloy surface and study effect of rare earth on properties. SEM and EDS were used to test thickness and composition of chemical plating; XPS was adopted to analyze valence state of rare earth element in plating coating; XRD was taken to analyze composition of plating coating through different heat treatments; microhardness tester was used to test hardness of plating coating through heat treatment; and electrochemical test was conducted to characterize corrosion resistance of titanium alloy and plating coating through heat treatment. Rare earth-modified thick coating was composed of a 70 μm NiP layer and a 30 μm Ni-P-Ce layer. The coating was formed by three elements including Ni, P and Ce with respective mass fraction of 89.94%, 10.03% and 0.03%. The element Ce was composed of three valence states of +4, +3 and 0. With the increase of heat treatment temperature, the coating gradually changed from amorphous to crystalline. The transformation occurred at 200~300 ℃ and the composition also changed. The hardness of coating increased and reached 1000HV after heat treatment at 400 ℃. The coating could effectively improve the corrosion resistance of titanium alloy substrate, but the corrosion resistance dropped dramatically as the heat treatment temperature increased. The optimum heat treatment temperature was 200 ℃ (the corrosion current density and polarization resistance were 0.2445 μA/cm2 and 155.464 kΩ respectively). The coating modified by rare earth was 100 μm thick plating coating. Rare earth cerium, nickel andphosphorus are co-deposited on the titanium alloy due to reaction. The heat treatment temperature has obvious influence on crystallization mode, composition and hardness, especially corrosion resistance.
Close