摘要:

AbstractThe nitrogen and carbon activities are the cardinal parameters for process control of nitriding, nitrocarburising, carburising, and carbonitriding. The essential elements of the thermodynamic background for the definition of the so called nitrogen and carbon activities in nitrided and carburised surface layers of iron based substrates are presented in a comparative manner. Choice of the distinct reference states is discussed in relation to the consequences for the interpretation of activities and equilibrium constants of the reactions. Practical examples are used to show how the nitrogen and carbon activities can be established; the activities can, for example, be used to determine the amounts of dissolved nitrogen and carbon. Also, knowledge of the nitrogen and carbon activities makes it possible to minimise and to control nitrogen gas pore formation and/or to avoid cementite formation in engineered surface layers.

ISSN:0267-0844    

DOI:10.1179/sur.1996.12.2.152

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractCobalt-silicon nitride composites were produced on mild steel by conventional electrocodeposition from a sulphate bath. These deposits showed better performance than pure cobalt in friction and wear tests against a hardened steel disc under dry sliding conditions. Changes of load and sliding velocity at the interface were also found to influence the tribological performance.

ISSN:0267-0844    

DOI:10.1179/sur.1996.12.2.163

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractTwo closed field unbalanced magnetrons with aluminium and molybdenum targets were used for the codeposition of Al-Mo coatings with different compositions. A pin on disc machine and a computer controlled potentiostat were used to evaluate the tribological and corrosion properties of the deposited alloys respectively. Results show that introducing molybdenum into aluminium coatings improves their poor tribological properties; Al-Mo coatings with different compositions showed low wear behaviour and for coatings with high molybdenum contents (>80% ) friction coefficients against steel as low as 0·18 were obtained. The addition of molybdenum to aluminium coatings reduced their tendency to corrode and corrosion current density in a marine environment.

ISSN:0267-0844    

DOI:10.1179/sur.1996.12.2.167

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

ISSN:0267-0844    

DOI:10.1179/sur.1996.12.2.169

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor