摘要:

AbstractTen materials with a wide range of microstructures and properties have been electrodischarge machined using copper and graphite electrodes with three pulse energies, and their machining rates, roughness, microstructure, micro hardness, cracking behaviour, and - for the white cast iron - dry sliding wear behaviour deternlined. Materials that are difficult to machine by conventional means (e.g. metal matrix composites, white cast iron, and high silicon cast iron) could be readily processed. Machining rates were approximately a linear function of the square root of pulse energy. A similar topography, which was difficult to quantify, was observed on all the materials. Surface roughness of the tool steel was a function of cube root of pulse energy. Hard surface layers occurred on the ferrous materials, but in some non-ferrous materials softening occurred. Extensive cracking occurred only in steels and cast irons containing a high concentration of chrOlnium. Electrodischarge machining increased the wear resistance of white cast iron fivefold.

ISSN:0267-0844    

DOI:10.1179/sur.1992.8.4.283

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

AbstractAn investigation was carried out to assess the corrosion resistance of duplex stainless steel that was surface alloyed with ruthenium. It was found that vapour deposited ruthenium on the surface of a duplex stainless steel improved the corrosion resistance, especially if the alloy is annealed after surface deposition has been carried out. The ruthenium apparently increases the corrosion potential to more noble values, and also inhibits anodic dissolution. This method promised a more economical technique of cathodic modification than bulk alloying.

ISSN:0267-0844    

DOI:10.1179/sur.1992.8.4.289

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

AbstractOne of the most useful combinations for coating cutting tools is a triple layer of TiC + TiCN + TiN. This combination gives combined wear protection: TiC has good adhesive wear resistance which protects the cutting tool from flank wear and TiN confers diffusion wear resistance which protects the tool from crater wear. As the number of coating layers was increased, keeping the overall coating thickness constant, the tool life improved when machining steels; the efficiency of the machining process was also improved since the cutting speed could be increased. The life of coated cutting tools when machining steel at different cutting speeds is examined and cutting tools with multilayer and single layer coatings are compared. Comparison is also made between multilayer TiC + TiN and TiC +Al2O3+ TiN coating combinations under the same cutting conditions.

ISSN:0267-0844    

DOI:10.1179/sur.1992.8.4.292

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor