The paper presents the problems with surface treatment of aluminium by anodizing techniques. The reasons for the spots on the anodized surface were investigated. Due not suitable anodizing process the remaining porosity in the layer was observed, which optical appears as a spot. Research with electron microscopy revealed that spots are consequence of different diffraction of light due presence of pores in the transparent anodizing layer.
F.04 Increase of the technological level
COBISS.SI-ID: 718506The paper presents different methods of working of Al-alloys in semi solid state. The Rheocasting method was tested for manufacturing of an automotive part. Presented are results of the failures analyses of experimental components manufactured by Rheocasting process and derermined are the reasons for the observed failures.
F.13 Development of new production methods and tools or processes
COBISS.SI-ID: 738218The microstructure of AISI M2 high-speed steel can be substantially modified by vacuum heat treatment. On that way the ratio in order to optimise the ratio between hardness and fracture toughness can be optimised. This ratio is significantly affected by the volume fractions of retained austenite and undissolved eutectic carbides, as well as the mean distance between these carbides. The value of fracture toughness values can be calculated by using a semi-empirical equation, based on the stress-modified critical strain criterion and the quantified microstructural parameters.
B.04 Guest lecture
COBISS.SI-ID: 763050Investigated duplex stainless steel LDX 2101 contains 54 % ferrite, the rest was austenite.The yield stress was 464 MPa, the strength 696 MPa, the elongation 45 % and toughness 291 J. The tensile tests showed that the best hot ductility are in temperature region among 1100 to 1250 oC, a little worse between 1100 and 1000 oC, below the 1000 oC the deformation strength was rapidly increasing. For optimal mechanical properties of LDX 2101 steel need to be solution heat treated after hot rolling.
F.04 Increase of the technological level
COBISS.SI-ID: 719274The data on rolling forces are important especially at lower temperatures of hot rolling, where at industrial rolling, to high stresses damaged the rolling stand. To establis the suitable technology it is important to make comparison of stresses and deformation strength at rolling of steels, those one already in production and those one not yet in production.
F.14 Improvements to existing production methods and tools or processes
COBISS.SI-ID: 749226