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D. Janicki

Abstract

The paper describes the application of an Yb:YAG disk laser with a maximum output of 3.3 kW for the butt welding of armor steel plates ARMOX 500T 3.6 mm thick. The influence of laser welding parameters such as laser power beam, welding speed, focal point position on weld quality and mechanical properties of joints was studied. A proper selection of disk laser welding parameters provides non-porous and cracks free fully-penetrated welds with the aspect ratio up to 6.4. There was approx. 40% reduction in the hardness of heat affected zone (HAZ) in comparison to hardness of the base material (BM). The hardness values at the weld metal and the BM were similar. The joints exhibited about 15% lower ultimate tensile strength when compared with that of the BM. Charpy absorbed energy of the joints was approx. 30% lower than that of the BM.

Open access

D. Janicki

Abstract

Diode laser surface alloying process was used to the in-situ synthesis of TiC-reinforced composite surface layers on the ductile cast iron substrate. The obtained composite surface layers were investigated using optical and scanning electron microscopy, and XRD diffraction.

It was found that the morphology and fraction of TiC phase is directly dependent upon both the concentration of titanium in the molten pool and also the solidification rate. With increasing titanium content, the fraction of TiC increases, whereas the fraction of cementite decreases. The TiC phase promotes a heterogeneous nucleation of primary austenite grains, what reduces a tendency of cracking in the alloyed layers.

Open access

D. Janicki, J. Górka, W. Kwaśny, K. Gołombek, M. Kondracki and M. Żuk

Abstract

Metal matrix composite (MMC) surface layers reinforced by WC were fabricated on armor steel ARMOX 500T plates via a laser surface alloying process. The microstructure of the layers was assessed by scanning electron microscopy and X-ray diffraction.

The surface layers having the WC fraction up to 71 vol% and an average hardness of 1300 HV were produced. The thickness of these layers was up to 650 μm. The addition of a titanium powder in the molten pool increased the wettability of WC particles by the liquid metal in the molten pool increasing the WC fraction. Additionally, the presence of titanium resulted in the precipitation of the (Ti,W)C phase, which significantly reduced the fraction of W-rich complex carbides and improved a structural integrity of the layers.

Open access

D. Cygan-Szczegielniak and B. Janicki

Abstract

The aim of this study was to determine the chemical composition of roe deer meat considering the animals’ sex and age and to estimate the content of amino acids in the meat from two selected groups of the animals, i.e. 2-3-year-old males and females. A further goal was to assess the biological value of proteins as compared to the FAO standard. The study has revealed that in proteins from the roe deer muscle tissue the content of exogenous amino acids (in g/100g) is higher by 20-30% on average comparing to the level of amino acids, in the FAO/WHO (1973) standard protein. Among the endogenous amino acids, the highest (in g/100 g of protein) and the lowest concentrations were found for glutamic acid and proline, respectively. The research has also shown that roe deer meat possesses a high content of protein and a relatively low content of fat.

Open access

T. Tański, W. Pakieła, D. Janicki, B. Tomiczek and M. Król

In this paper, the influence of a laser surface treatment on the structure and properties of aluminium alloy has been determined. The aim of this work was to improve the tribological properties of the surface layer of the EN AC-51100 aluminium alloy by simultaneously melting and feeding silicon carbide particles into the molten pool. The silicon carbide powder was introduced into the liquid metal using a gravity feeder within a constant feed rate of 1 g/min. A high power diode laser (HPDL) was used for remelting. Laser beam energies used in experiments were 1.8 kW, 2.0 kW and 2.2 kW, combined with the constant velocity of 50 mm/min. As a result of the laser treatment on the aluminium alloy, a composite layer with greater hardness and wear resistance compared to the based material was obtained.

Open access

K. Labisz, T. Tański, D. Janicki, W. Borek, K. Lukaszkowicz and L. A. Dobrzański

Abstract

In this paper are presented the investigation results concerning microstructure as well as mechanical properties of the surface layer of cast aluminium-silicon-copper alloy after heat treatment alloyed and/ or remelted with SiC ceramic powder using High Power Diode Laser (HPDL). For investigation of the achieved structure following methods were used: light and scanning electron microscopy with EDS microanalysis as well as mechanical properties using Rockwell hardness tester were measured. By mind of scanning electron microscopy, using secondary electron detection was it possible to determine the distribution of ceramic SiC powder phase occurred in the alloy after laser treatment. After the laser surface treatment carried out on the previously heat treated aluminium alloys, in the structure are observed changes concerning the distribution and morphology of the alloy phases as well as the added ceramic powder, these features influence the hardness of the obtained layers. In the structure, there were discovered three zones: the remelting zone (RZ) the heat influence zone (HAZ) and transition zone, with different structure and properties. In this paper also the laser treatment conditions: the laser power and ceramic powder feed rate were investigated. The surface laser structure changes in a manner, that there zones are revealed in the form of. This carried out investigations make it possible to develop, interesting technology, which could be very attractive for different branches of industry.