Effects of propylamine and ethylenediamine intercalation of α-ZrP on the corrosion resistance and tribological properties of electroless Ni-B coatings
Liping Yan, Siming Yan, Yi He, Yi Fan, Xinyu Cheng, Huilian Zhou, Jiamin Zhong, Zhiyuan Li, Jinxue Song, Hongjie Li
Abstract
In this study, propylamine and ethylenediamine intercalated α-ZrP nanocomposites (denoted by P-α-ZrP and E-α-ZrP, respectively) were synthesized. The effects of propylamine and ethylenediamine intercalated α-ZrP nanocomposites and their reinforcements on the corrosion resistance and mechanical properties of Ni-B coatings were investigated and compared. The morphology and structure of the three composites were characterized using transmission electron microscopy , atomic force microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, infrared spectroscopy, thermogravimetric analysis , and particle size analysis . Both propylamine and ethylenediamine intercalation increase the layer spacing of α-ZrP, but do not change the lamellar structure of α-ZrP. The EIS test results show that both Ni-B/P-α-ZrP and Ni-B/E-α-ZrP composite coatings have significantly lower corrosion rates than Ni-B and Ni-B/α-ZrP composite coatings. Compared to Ni-B/α-ZrP, the corrosion rates are reduced by 32 % and 76 % respectively. The R ct values for Ni-B/P-α-ZrP and Ni-B/E-α-ZrP composite coatings are also distinctly higher than Ni-B/α-ZrP, with Ni-B/E-α-ZrP having the highest values. In addition, Ni-B/P-α-ZrP and Ni-B/E-α-ZrP composite coatings are both harder than Ni-B/α-ZrP and have lower average coefficients of friction and wear rates than Ni-B/α-aZrP. Among them, the Ni-B/E-α-ZrP composite coating has the highest microhardness (1163.64 ± 21.20 HV) and the best wear resistance. The wear rate is reduced by 87 % and 65 % compared to Ni-B and Ni-B/α-ZrP composite coatings respectively. In conclusion, both P-α-ZrP and E-α-ZrP are better than α-ZrP in terms of enhancement, with E-α-ZrP being the best.