ISSN:0267-0844    

DOI:10.1179/sur.1987.3.4.271

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

ISSN:0267-0844    

DOI:10.1179/sur.1987.3.4.274

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

ISSN:0267-0844    

DOI:10.1179/sur.1987.3.4.277

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

ISSN:0267-0844    

DOI:10.1179/sur.1987.3.4.289

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

ISSN:0267-0844    

DOI:10.1179/sur.1987.3.4.292

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

AbstractIn repairing heavily worn surfaces, significant benefits are demonstrated for incorporating preplaced solid bars along with standard weld deposition and hardfacing techniques.

ISSN:0267-0844    

DOI:10.1179/sur.1987.3.4.297

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

AbstractMCrAlY coatings (M = Ni, Co, Fe alone or in combination) are currently used to protect gas turbine blades and vanes from oxidation and hot corrosion. The coatings are required to be fully dense and well bonded to the substrate. They are formed either by electron beam evaporation or by low pressure plasma spraying. Another possible route is to form them by normal atmospheric plasma spraying, followed by remelting with a laser to remove porosity and other defects. The feasibility of this approach has been investigated by melting plasma sprayed NiCoCr AIY coatings on a Nimonic 75 substrate. This work focuses mainly on the effect of various laser processing parameters on the structure of remelted layers. Preliminary data on the hot corrosion properties of the laser melted coatings are also presented.

ISSN:0267-0844    

DOI:10.1179/sur.1987.3.4.299

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

AbstractSome new ideas on diffusion modelling under ion bombardment heat treatment conditions are presented. The model put forward may explain why ion bombardment treatment times can be much shorter than those for conventional processes. Some of the problems are discussed, such as the influence of ion bombardment on treated surface structure and vacancy diffusion.

ISSN:0267-0844    

DOI:10.1179/sur.1987.3.4.310

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

AbstractThe wear resistance and durability of 40 mm thick·high chromium iron weld surfacing deposits have been investigated with reference to the low stress abrasion conditions experienced by the work roll of a coal crushing mill. It was found that an underlayer of austenitic stainless steel greatly reduced cracking and spalling of the deposit. The variations in welding conditions tested had relatively little effect. A modified ASTM G65 dry sand/rubber wheel abrasion test with a 3 kg load was shown to give results that correlated well with service experience. Extensive compositional testsindicated that carbon content was the lnajor factor controlling hardness and abrasion resistance, through its influence on chromium carbide volume fraction. The optinlum carbide content was found to be 55-65%, since above this range brittle fracture becomes excessive.

ISSN:0267-0844    

DOI:10.1179/sur.1987.3.4.313

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor

摘要:

AbstractA nickel black solar selective coating, which is based on rich oxide-nickel metallic matrix deposited on nickel foil, was deposited by sputter ion plating in a reactive atmosphere. The optical properties of the nickel cermet are evaluated experimentally. A theoretical model of the proposed structure yields comparable but not identical results. The average value of the near normal hemispherical total solar absorptance as averaged over the air mass 2 solar spectrum is 0.95±0.003. The near normal total thermal emittance, however, is 0.083±0.005. The characteristics and stability of the coatings are also examined.

ISSN:0267-0844    

DOI:10.1179/sur.1987.3.4.321

出版商:Taylor&Francis    

年代:1987

数据来源: Taylor