Journal of Applied Materials Engineering

In this paper, we present comparative investigations. We examined two kinds of ceramic materials used to produce bricks for isothermal cleading of the riser heads of middle and large steel castings. The ceramic materials were characterised by a low specific density (No. 1 − ρ = 0.854 g/cm³; No. 2 − ρ = 0.712 g/cm³). Thermal conductivity tests at a transient heat flow were performed by analysing the heating process of samples taken from the tested ceramic bricks, placed in a special mould in which metal was poured, and by recording the cooling process of the casting. The method proposed in this paper for the determination of samples’ thermo-physical properties is based on measuring the temperature field of the casting–sample system by means of thermocouples situated in various measuring points; it allows the direct investigation of cooling and solidification processes of metals in sand moulds. The heating process of the ceramic samples was analysed by measuring the temperature in five points situated at various distances from the heating surface (casting–sample surface). A large difference in the heating rates of samples of different materials was revealed in our comparative investigations, which indirectly indicated the materials’ heat abstraction ability from the casting surface. The ceramic material characterised by a lower density much slowly conducted heat and, therefore, appeared to be a better material for insulation cleading. At the depth of 40.0 mm, we measured differences in the heating degree corresponding to more than 190 °C. The aim of this comparative study was the evaluation of the suitability of porous insulating materials as cleading of riser heads used in the production of large steel castings. Full article

This paper presents the results of the processes of treating aluminum matrix casting materials with the addition of a ceramic phase. The matrix of the composite material was an Al-Si7 casting alloy with addition of 2 mass% Mg. The volume fraction of the reinforcing phase in the form of silicon carbide ranged from 5 to 15 vol.%. Preliminary machining tests were carried out at the Mori Seiki NL2000SY turning and milling center. The cutting properties were evaluated during longitudinal turning. Cutting tests were carried out using tools made of polycrystalline diamond, regular boron nitride, and cemented carbides. The nature of VBB wear was checked in accordance with PN-ISO 3685:1996. The influence of machining parameters (cutting speed, feed, cutting depth) on the value of cutting tools temperature was determined. An analysis of the chip shaping mechanism during machining was performed at various cutting parameters. The tests were carried out using the FLIR A655 thermal imaging camera and the fast Phantom MIRO M310 fast camera. Cast composite materials were also subjected to the processes of waterjet cutting, EDM cutting, and EDM drilling (EDM electro discharge machining). Full article

Wear resistance, which is one of the main technological quality features of machine parts and tools, is determined by the properties of their surface layer. The demand for high-quality products forces manufacturers to use modern structural and tooling materials as well as efficient and cost-effective methods of their treatment. The paper presents the results of research on selected properties of tools made of tool steels and sintered carbides, as well as parts made of aluminum alloy subjected to selected surface treatment processes, such as mechanical (grinding, turning, milling, burnishing) and thermo-chemical (nitriding, sulfonitriding) processes, and physical vapor deposition (PVD) of coatings. The presented results, including analyses of the surface geometric structure, microstructure, and microhardness, as well as tribological and machining properties of selected materials, indicate the possibility of improving the functional quality of tools and machine parts. Full article