Key Engineering Materials Vol. 635

Abstract: Currently, the automotive industry used sheets of different qualities. The most common include IF (inter Interstitial Free) steel and alloyed steel. Use the sheet quality depends on the point of application in the production car. Testing and product testing is a standard part of the process of innovation and production itself. Testing of automotive steels under dynamic conditions is increasingly important. Changing the hardness HV 1 was performed on the fractured bars on the static and dynamic loading conditions. Tests were made on steel IF and S 460.

Abstract: Fluidity is the basic foundry property. The fluidity of AlSi alloy in real condition with computer simulation were compared. In this test was used two types of molds: horizontal molds with tree canals and vertical molds with six canals wich had different diameter (4,5; 6,5; 8,5; 10,5; 12 and 14 mm). As experimental material was used AlSi10MgMn (EN 1706) alloy. Range of pouring temperature was between 605°C to 830°C. NovaFlow&Solid soft commercial software package was used for numerically simulating the fluid flow of molten metal. The model of fluidity test was created by CAD system CATIA V5 R19. Measurement systems analysis (MSA), the analysis of the variance (ANOVA), t-test and the analysis of correlation were used for the evaluation. Youden plot was used for evaluation of the impact of operators on the errors. Values of fluidity for each temperature level obtained by the horizontal mold have a high degree of agreement with those obtained by computer simulation. On the contrary, the values, obtained by the vertical mold are more sensitive to the operator. This fact caused the match between the simulation and a practical experiment is only partial.

Abstract: The aim of the paper is the automation of experimental determination of isotropic and orthotropic background stresses by the tools of the photoelasticity and by the effects of the isolines’ field recorded through the recording medium.

Abstract: This paper presents the results of research aimed to measuring the corrosion properties of automotive steel sheets. The degree of deformation influence to the corrosion properties of the steel sheet for car body parts has been proven by the modern methods of corrosion monitoring such as Electrochemical Impedance Spectroscopy. Corrosion rate was assessed using electrochemical methods in 0.1 M solution of NaCl. Experimental studies have pointed out if degree of deformation increases the corrosion rate of the steel sheet increases as well.

Abstract: Multilayer packages represent a traditional application of Low Temperature Co-fired Ceramics (LTCC) in electronics. Nowadays, the use of the LTCC is becoming very popular in construction of microstrip filters applied in GHz (HF) range. Research and development on the LTCC microstrip filters performed at Technical University of Kosice has revealed yet unexplored possibility of using various LTCC up to 13 GHz and in this way a possibility of microelectronic structure production applied in the communication application. In this study, we will find out a method of shrinkage instability elimination as well as a correlation between shrinkage and mechanical properties. Dimensional accuracy and flatness of the ceramic substrate is the most important factor in the development of the microstrip filters applied in the HF area. The paper reviews LTCC processes from this point of view and shows that the main aspect of LTCC technology is targeting a more precise manufacturing tolerance control in which electrical performance (scattering parameters) is sensitive to the HF area such as realization of fine line microstrip structure.

Abstract: This paper deals with description of properties of selected natural materials mainly theirs shelter function. The investigated materials are horsetail and walnut shell. Both natural materials have porous shell/tubular structure. Walnut shell provides natural shield cover for fruit with gradient distribution of porosity and membrane function. In case of horse tail, except the gradient distribution of porosity there is also the gradient change of chemical composition along the cross-section.

Abstract: Modeling sheet metal forming operations requires understanding of the plastic behavior of the sheet metal along the non-proportional strain paths. Measurement of hardening under reversed uniaxial loading is because of its simplicity very effective mechanical test to achieve several important features of material behavior. With the reversed uniaxial loading can be examined features as Bauschinger effect, work hardening stagnation, permanent softening etc., which are necessary to defined kinematic hardening in the numerical simulations. The biggest problem of uniaxial reversed loading is buckling of the sheet metal during the compression phase. In this article is described development of the simple fixture, used for the reversed uniaxial loading and results of tension-compression test for the steel DP 600 in various pre-strain levels are specified.

Abstract: Current trend in increasing steam parameters in ultra-supercritical (USC) boilers requires new materials not only for membrane walls, headers and pipelines but also for superheater and reheater tubes. Newly developed austentitic steels Super304H, TP347HFG and HR3C exhibit superior resistance in steam thanks to their fine-grained microstructure, especially in case of Super304H and TP347HFG. The paper presents the results of verification of properties of these steels tubes including creep resistance of the base metal and welded joints, which show promising level of long-term creep strength of the base metal and weld joints and these results are supplemented by some new knowledge about the development of the microstructure of these steels, especially sigma phase appearance.

Abstract: The paper describes experimental stamping punch production from the view machinability and quality of stamping punch active surfaces. The tin car-body stamping punch has been chosen as a subject of experimental work. Two unconventional materials such as Textit J and Fibroflex 5 have been chosen for stamping punch. Milling strategies have been proposed, optimized and verified using CAM software SolidCAM considering the maximum Scallop Height. The final surface quality on selected areas of stamping punch shaped surface has been evaluated by surface roughness parameters Ra and Rz. These have been compared to Scallop Height set in CAM software. Manufactured areas on shaped surface were optically evaluated as well.

Abstract: The main objective of the present paper is the characterization of the mixed-mode delamination in sandwich plates. To this purpose a mixed-mode delamination failure model is proposed. Then, the failure model is implemented in ANSYS code to calculate the damage propagation parameters. The analysis is based on the Finite Element Method and interface techniques. Within the interface finite element modeling there are calculated the individual components of spring reaction force, relative displacement and energy rate release along the lamination front.