Applied Mechanics and Materials Vol. 474

Abstract: The contribution describes complex solution of stamping punch production from the view manufacturability and quality of stamping punch active surfaces. The application of proposed procedure is shown as an example of manufacturability experimental and production stamping punch designed for complex parts production. There is also proposal of both, the production process and strategies for stamping punch manufacturing. The quality of manufactured parts was reviewed according to its manufactured surfaces by optical evaluation and the roughness measurement on selected areas as well.

Abstract: In this paper we consider design of a digital electromechanical positioning system that ensures controlled change of the jerk. A system that is formed from a load and an actuating device is used as an object. For the proposed sinusoidal change of the jerk, the appropriate changes of the acceleration, velocity and displacement were found.. The control algorithm which ensures the motion of the object with sinusoidal change of the jerk so that the requirements which are related to the maximum values of the acceleration, velocity and displacement are satisfied, is also proposed. The digital feedforward and feedback controllers that are realized this algorithm are designed. Furthermore the simulation of that system is performed, which is confirmed the proposed theory.

Abstract: The article presents a design for production of shaped surfaces with the use of 3D milling machine and its control programs in various programming means in order to evaluate the accuracy of produced shaped surfaces as well as their relation to a particular program. The shaped surfaces are mathematically defined. Their advantage lies in possibility of being checked with the use of 3D metre and optimising their shapes with the available mathematical functions. Derivatives come as typical example enabling us to search e.g. function extremes. Programming of the 3D milling machine Emco-Mill control program is done with the use of CATIA V5 and EqCAM. The produced shapes accuracy is checked with the use of 3D Carl-Zeiss coordinate system and a particular software. The solution results in verification and execution of two control programs for 3D shaped surfaces and in evaluation of the mathematically defined shaped surfaces accuracy.

Abstract: The paper deals with the effects of CAM data needed to produce desired quality of shaped surfaces in forming dies making. In general, the input CAM data have strong influence to the final surface quality. The shaped surfaces 3D milling has been modeled as end ball milling of the surfaces with defined inclination. The end ball milling is the most common way to finish shaped surfaces. Directions of the milling tools motion and applied cutting conditions have been used to simulate data when setting milling strategies. The resultant machined surface quality has been identified in terms of the surface roughness. The paper introduces recommendations applicable to the programming of the different types of milling strategy when producing form surfaces.

Abstract: This paper present result of a study evaluating the influence of path generation strategy on mechanical properties of Fused Deposition Modeling (FDM) prototypes. Several scientific studies were researching the problematic of path generation and internal structure of FDM prototypes. Mostly the influence on mechanical properties was observed. This paper is aimed on determine the influence of outline number and internal air-gap on tensile strength of parts built from ULTEM 9085. For this two variables was determined the influence on built time and consumption of modeling material. Result show that proper model orientation when the orientation of load is known, can help to reduce the build time and material consumption.

Abstract: This paper analyzes the effect of the punch-die gap on blanked edge quality in fine blanking. The objective is to determine basic mechanical properties of galvanized multiphase steel sheets with a thickness of 0.75, 0.80 and 0.85 mm by a single-axis tensile test, determine the effect of the punch-die gap on plastic phase depth [h_v] expressed as the relation of h_v to a₀, and, finally, determine the effect of material properties of blanked sheet metal on blanked edge quality expressed as the relation of h_v to a₀.

Abstract: The article deals with the creation of models for the analysis of plastic zones generation in ductile cast iron. The aim is the study of the microplasticization process near the graphite particles border. In creating the graphite particle model there is randomly chosen shape and orientation of the particle. The basic characteristic of the shape is ovality (the ratio of the inscribed circle to the circumscribed circle). The size of plastic deformation and the size of the plastic area are monitored by the microplasticization process analysis. The results are statistically elaborated to determine the relationship between graphite particle ovality and microplasticization caused by an inclusion.

Abstract: The contribution deals with comparison of microstructure, mechanical properties and fatigue properties of synthetic nodular cast irons with a different ratio of steel scrap in a charge. Chemical composition of individual meltages was regulated alternatively by ferrosilicon (FeSi) and carburizer or metallurgical silicon carbide (SiC). The paper shows that SiC additive positively influences the microstructure, mechanical properties as well as fatigue properties of nodular cast iron, especially in the meltages with higher ratio of steel scrap in the charge. Moreover, production of synthetic nodular cast irons with SiC additive is economically advantageous.

Abstract: On the basis of large changes in temperature during the welding process technology, there is a shape change or welded parts of tensions. Stress and deformation of the welded material formed as a result of heat delivered to the weld zone and its surroundings. Uneven heating or cooling, and fixed mounting welded parts may cause the formation of stress in welded material during the welding process. Causing local, or overall deformation of welded parts. That is why it is necessary to know the temporal distribution of temperature and stress generated during welding. Stress or strain cycle is the result of welding thermal cycles. It is possible to determine the time courses of thermal cycles with different methods. The most commonly used method are experimental, analytical and numerical. Currently most often to predict stresses and deformations using the methods of the modeling and numerical simulation used FEM. Which any application methods for solving specific problems in the field of welding, it is possible to obtain such results. Such as residual thermal stress and deformation of welded materials or changes in the structure of the different phases of the material in the heat affected zone (HAZ). The residual thermal stress and deformation, changes of phase structure of the material in the heat affected zone have a great impact on the quality and strength of the weld joint.

Abstract: The coefficient of friction for the bronze material (CuZn25Al6) with inset graphite beds is investigated in the present paper. Friction coefficient was investigated experimentally by the testing machine Tribotestor`89 which uses the principle of the ring on ring method. Tribotestor`89 machine may be classed to the rotary tribometers. The tested sliding pairs were of the same material. The internal bushing performed a rotational movement with constant sliding speed (v = 0.8 m s^-1). The external fixed bushing was exposed to the normal load, which was of different sizes and different variations. Process of load was increased from level 50 N to 200 N (400 N, 600 N) during run up 600 s, after the run up the appropriate level of load was held.The forth test had a rectangular shape of loading with direct current component 400 N and the amplitude 200 N period 600 s, the whole test took 1800 s. The obtained results reveal that friction coefficient decreases with the increase of normal load. Further, that the coefficient of friction was found smaller at constant load, as compared to rectangular shape of loading.