Mikrostruktur‐Untersuchungen zum Schwingungsverschleißverhalten von Nickelkomposit‐ und Ni‐P‐Schichten

Abstract

Schlüsselworte: Gefügecharakterisierung, Schwingungsverschleiß, Martenshärte, Galvanische Nickelnanokomposite, Chemisch Ni-P-Schichten In many industrial applications, oscillating sliding wear leads to serious damage of construction components. To avoid this, different layers of electroplated nickel and nickel composites as well as chemically deposited nickel phosphorus layers are used and/or tested. The performance of these layers under oscillating sliding wear was characterized. Additionally microstructure characterisations took place regarding grain size, particle content and distribution as well as concerning crystallization and development of tetragonal phase nickel phosphide. These results correlate well with the Martens hardness of the layers and contribute to understand the oscillating sliding wear characteristics of the examined layers. Heat treated Ni-P layers achieve twice the hardness of nickel dispersion layers; however, fail under oscillating sliding stress by embrittlement, cracking and debonding. On the other hand dispersion-hardening nano composites with TiO 2 clearly exhibit a more favourable tribological behaviour. A solid content of approx. 3 vol-% leads to dispersion and fine grain hardening effects, which cause good protection against oscillating sliding wear; thereby the Ni-matrix remains ductile. The incorporation of very hard particles (SiC) intensifies the oscillating sliding wear process due to the abrasive effect of the particles.