Rafał Bogucki
Technical Transactions, Volume 12 Year 2017 (114), 2017, pp. 231-242
https://doi.org/10.4467/2353737XCT.17.222.7765Electrodischarge machining (EDM) can be used as an alternative machining method compared to conventional ones, especially while very good surface integrity and high machining accuracy during machining of difficult-to-cut materials is needed. In EDM, the dielectric liquid has a crucial influence on the technological material surface integrity since it ensures the occurrence of controlled electrical discharges between the tool and the workpiece, cooling and solidification of gaseous EDM debris, removing erosion products and also dispersing heat generated during the process. In the paper, the influence of a carbonbased and a water-based dielectric liquid on the selected structural and morphological characteristics of 304 stainless steel after EDM sinking was investigated. The surface roughness, micro hardness and quality as well as the chemical changes after the corrosion test of machined surfaces were analysed.
Rafał Bogucki
Technical Transactions, Mechanics Issue 3-M (21) 2015, 2015, pp. 71-78
https://doi.org/10.4467/2353737XCT.15.177.4382Annealed samples of commercial purity aluminium (1050) were processed by Equal Channel Angular Pressing (ECA P) at room temperature for up to eight passes. ECA P was conducted by using three processing routes (schemes). Tensile tests and micro hardness were conducted to evaluate variation of mechanical properties after each pass. Analysis of fractography was carried out due to investigate a fracture of the samples. The results showed that all the schemes had similar micro hardness values – around 50 HV. The tensile test results showed that the highest yield strength was achieved in the second scheme after eight passes – 186 MPa – while elongation maintained at the level of 17.4%. The value of yield strength achieved increased more than six times in proportion to annealed condition.