Investigation of tribological and mechanical properties of Nb-Al-N coatings before and after annealing
Coatings Nb-Al-N were deposited on a silicon substrate under argon and nitrogen by magnetron sputtering at a substrate temperature of 350 °C and a constant current of 250 mA at the aluminum cathode. The analysis of the dependence chemical composition, morphology, structure and mechanical properties of the annealing temperature were performed for different series of coatings. Coatings demonstrated high thermal stability after annealing to 1000 °C.
Certain features of high-dose and intensive implantation of Al ions in iron
Abstract Using a proton microbeam PIXE and RBS, a formation of local surface segregations of aluminum in an iron layer has been found, for the first time, at an initial stage of high-dose intensive implantation (from 8×1016 to ×1017 cm−2). Using a slow positron beam, a profile of vacancy defects, which depth is comparable to a depth profile of Al ions implanted into iron with 5×1017 cm−2 has been measured. Complex carbides (Fe3Al)C and Fe3C have been found in a near surface layer (TEM measurements) as well as segregations of an ordered phase Fe3Al (which with a dose increased are partially amorphized). In addition, high dislocation density of 1.2×1010 cm−2 has been found in the near surface layer, and fields of elastic stresses are formed, which results in the increased friction wear resistance and microhardness.
Finite Difference Modeling on the Temperature Field of Substrate in Friction Surfacing
Friction surfacing is an advanced process of great potential, especially in the field of repair and reclamation of worn and damaged components. As a kind of thermal processing technology, the temperature profile and changes of the substrate in friction surfacing are important factors to get coatings of high quality. In this paper, the temperature field of the substrate during the process is simulated by finite difference method. The results are consistent with experiments, reappearing the temperature change of the substrate during friction surfacing, allowing further study on figuration and quality of coatings.