作者: Jaime Taha-Tijerina , Demófilo Maldonado Cortés , Karla Aviña-Camarena , Carlos Dominguez-Rios , Roal Torres-Sánchez
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摘要: • 1946-First reports of nickel electroless process [000]• Presently, deposits of Ni− P:(W, Mo, Co) and Ni− B are used in automotive, chemical, aerospace, oil & gas, electronic and textile fields as well as to improve medical instrumentation [1–4]• Two commercial processes to deposit Ni− B electroless coaLngs: one uses borohydride and the other dimethylamine borane (DMAB) as the reducing agents. The structural characteristics idenLfied in the Ni− B coaLngs depend on the B content: a) if content is< 2wt.%, microstructure consists of a solid solution of boron into microcrystalline nickel with columnar structure; b) if content is between 2 and 6wt.% a mixture of microcrystalline and amorphous phases are formed, c) if content is~ 6wt.% the coating becomes totally amorphous.• With thermal treatments hardness on Ni− B coaLngs can be similar to that of hard chromium with high wear resistance. The only reported disadvantage is a corrosion resistance slightly smaller than Ni− P alloys [5-9]• Heat treatment improves hardness and the adhesion of Ni–B deposited on steel [10]• Further improving the electroless Ni-B coating conditions are compared in wear tests versus hard chromium, electroless Ni-P, cubic boron nitride, and titanium nitride, reporting lower wear and a lower COF [7, 11–14]• In previous research, electroless Ni-B baths are usually prepared with more than four reagents, and in a great majority they use heavy metal salts (Pb and Ta) as a bath stabilizer.• Health regulations and environmental these last salts are being banned.• In this work we use a bath of four components, easy to control and relatively low temperature (65 C), no stabilizers …