摘要:

AbstractTi–B–N films,∼3μm in thickness, containing 5–16 at.-%B have been deposited on W18Cr4V high speed steels and stainless steels using ion plating. The Vickers microhardness of the films was as high as 35–45 GN m-2(load 0·25 N) and the critical load during scratch tests 11–15 N. The film/diamond stylus sliding friction coefficient is 0·086–0·097 (load 8·8 N). X-ray and electron diffraction analyses have indicated that the film consists mainly of fcc TiN with dispersed simple orthorhombic TiB, cubic BN, and simple hexagonal Ti–B–N phases. SEM and TEM micrographs of longitudinal and cross-sections of the films show that the film has a very fine, dense fibrous nanocrystalline structure, with grain sizes ranging from several to tens of nanometres. The titanium, boron, and nitrogen contents are homogeneous within the film. A diffusion zone has been shown to exist at the film/substrate interface by ion probe microanalysis and EDAX examination.

ISSN:0267-0844    

DOI:10.1179/sur.1990.6.1.41

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractA new ceramic coating technique using a high power density carbon dioxide laser has been developed, which makes possible the practical production of solid electrolyte layers for high temperature solid electrolyte fuel cells. Initial experiments have been performed using alumina and copper substrates, which were coated with 91ZrO2–9Y2O3. The crystal structure of the coated layer was cubic. No evidence of monoclinic or tetragonal crystals was found.

ISSN:0267-0844    

DOI:10.1179/sur.1990.6.1.45

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractDilution of a hardfacing alloy by the substrate can cause significant reductions in the hardness and wear resistance of the deposited coating. Application of a second layer of hardfacing alloy is one of many techniques used to minimise dilution. However, research into the hardfacing of grey cast iron by spraying and welding processes to resist abrasive wear has shown that, in general, no benefit is derived from the application of two layers rather than one layer of alloy: application of the second layer therefore appears to be economically unwarranted.

ISSN:0267-0844    

DOI:10.1179/sur.1990.6.1.49

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractThe properties of plasma sprayed WC–Co coatings have been improved by infiltration with copper alloys. A Cu–Ni–P alloy and BCuP–3 solder show excellent results as infiltrant materials, and infiltration can be carried out at lower temperatures than conventional infiltration with Ni–P alloys. The hardness of the infiltrated coatings is 1400–1500 BV, which compares favourably with that of cemented carbides. The higher hardness results in considerably lower rates of wear than with as sprayed coatings.

ISSN:0267-0844    

DOI:10.1179/sur.1990.6.1.52

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

AbstractScratch testing using hemispherically tipped diamond styluses of tip radii 100 and 250 Jim has been used to study the surface deformation and frictional behaviour of thin (2–5μm thick) coatings of TiN and TiC deposited on steels by proprietary CVD and PVD processes. For both the CVD and PVD samples, the coefficient of friction was found to increase with increasing normal load. Analytical evaluation of the data indicates that plastic ploughing appears to dominate the deformation of the coating with adhesion playing little part in the friction process. The dominance of ploughing was confirmed by SEM observations. Further, analysis of the data for scratch tracks contained wholly in the coating showed that, depending on normal load, plastic flow in the surface layers of the substrate due to stresses transmitted through the coating could also significantly influence frictional behaviour.

ISSN:0267-0844    

DOI:10.1179/sur.1990.6.1.55

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor