摘要:

AbstractBillions of pounds are lost every year in industry as a result of worn parts and wastage of materials. In view of the need for energy and materials conservation, the hardfacing of parts or components must be considered as a production process from the design stage, rather than merely a reclamation process. By applying hardfaced coatings to parts or components subjected to breakdown through wear, their working lifetime can be extended by up to 5 times. The present paper outlines the types of wear and choice of hardfacing alloy, as well as spraying and welding deposition processes.

ISSN:0267-0844    

DOI:10.1179/sur.1995.11.1.43

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractA novel mechanical surface treatment using laser induced shock waves has been applied to the wrought aerospace aluminium alloy 7075–T7 351 to improve its fatigue behaviour. Optimisation of the shock parametersand mechanical effects produced by the treatment have been investigated and fatigue performance is compared with that of conventionally shot peened specimens. It is shown that use of a one-dimensional Lagrangian hydrodynamic shock wave analysis code allows the attenuation of shock waves to be simulated and the depth of the plastically affected zone to be predicted. An analytical model developed to predict residual stress levels gave good agreement with experimental values. The fatigue limit of laser shocked specimens was found to be higher than that following shot peening. This large increase (22%) appeared to result from the high levels of residual stress and the greater extent of the stress field in the laser treated specimens and, most importantly, from the preservation of the surface condition. All these factors greatly increased the duration of the crack initiation stage of fatigue, as was confirmed by ac potential drop measurements.

ISSN:0267-0844    

DOI:10.1179/sur.1995.11.1.47

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractSurface modification of polymers has been investigated using low temperature plasma techniques such as plasma grafting and plasma immersion ion implantation. The polymers studied include polyethylene terephthalate tyre cord, silk fabrics, and polyimide films and the changes in molecular structure of the polymer surface were analysed with the aid of X-ray photoelectron spectroscopy and attenuated total reflection infrared spectroscopy.

ISSN:0267-0844    

DOI:10.1179/sur.1995.11.1.53

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractThe following is an English translation of Japanese Industrial Standard G0562, compiled on behalf of the Divisional Council on Iron and Steel, which is reproduced as an information service to SE readers. Dr Norio Kanetake, a member of the SE Editorial Panel, chaired the committee most closely involved with the preparation of this standard.

ISSN:0267-0844    

DOI:10.1179/sur.1995.11.1.57

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractResidual stresses have a strong influence on the properties of nitrided parts. Therefore knowledge of their origin and magnitude is of great interest and aprerequisite if changes in the stresses are intended. From the relevant theories of residual stresses in gas nitrided materials it can be concluded that stresses which are generated during nitriding can be reduced by plastic deformation and increased during cooling from nitriding temperature to room temperature. The increase in residual stresses should be a result of the volume misfit generated by different thermal expansion coefficients of the compound layer and the steel matrix. The theories mentioned have not thus far been confirmed by experimental work. Therefore one aim of the investigations was to clarify the origin of residual stresses as well as the different influences on the formation of residual stresses, especially during cooling from nitriding temperature to room temperature. Previously, residual stresses of nitrided parts could only be measured after nitriding. In the present work it will be shown, for the first time, that residual stresses cansuccessfully be determined in situ during the gas nitriding process by a special nitriding device installed in an X-ray diffractometer.

ISSN:0267-0844    

DOI:10.1179/sur.1995.11.1.61

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractHigh velocity oxyfuel (HVOF), air plasma spraying (APS), and low pressure plasma spraying (LPPS)techniques were used to deposit WC–Co and APS was used to deposit A12O3–TiO2coatings on ASTM 4130 steel in a study of the effect of process selection on the friction and wear of the coatings under dry sliding conditions in air. The LPPS WC–Co, which had a cobalt matrix with few brittleη-carbides (CO3w3C and C06w6C), small and evenly dispersed WC, and high residual compressive stress, was most abrasive to Al2O3–TiO2.

ISSN:0267-0844    

DOI:10.1179/sur.1995.11.1.66

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractA technique for examining microstructure is described which enables observation of fracture sections through hardness indentations and scratch tracks on TiN coatings, thereby clarifying the nature of the deformation and fracture behaviour caused by these tests. Particular use is made of high resolution scanning electron microscopy to observe fine detail, with backscattered mode employed for maximum crack contrast.

ISSN:0267-0844    

DOI:10.1179/sur.1995.11.1.71

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

AbstractElectrodeposition is widely used to deposit a variety of metals and alloys. Although high rates can be achievedusing this technique, there is limited control over the microstructure of the deposits and in many instances the use of toxic precursors and disposal of toxic effluents has to be considered. This has spurred the development of alternative deposition processes. The Jet Vapor Deposition™(JVD™) process is a rapidly emerging‘green’technology which allows control of microstructure at high deposition rates. A brief discussionof the principles of JVD and representative applications in the deposition of metals (such as copper and gold) and alloys (Cu–Ag and Ag–Sn) are presented.

ISSN:0267-0844    

DOI:10.1179/sur.1995.11.1.75

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

ISSN:0267-0844    

DOI:10.1179/sur.1995.11.1.87

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor