Bartosz Gapinski

Topographic inspection as a method of weld joint diagnostic

The paper demonstrates a topographic inspection in the specific context of three kinds of inspection methods of austenitic stainless steel welds. Visual and metrological inspection was analysed during tungsten inert gas (TIG) welding tests, showing the non-destructive techniques: X-ray, computed tomography, and surface profilometry. The article is a response to the lack of information, especially in the area of non-destructive techniques suitable for wide practical application. The Paper presents advantages and drawbacks of the analysed diagnostic methods and a classification of conventional and specific welded joint flaws. The most important defect in practical applications determining reliability of a welded joint is cracks. This kind of diagnostic is based on the obtained information about anisotropic and inhomogeneous volume under consideration in the heat-affected zone of a weld.

Uncertainty in CMM Measurement of Roundness

In the paper, the possibilities of the Coordinate Measuring Machines application for the roundness measurement have been discussed. The basic assumptions for this kind of measurement have been presented. The simulation results have been presented, as well as the experimental measurement results. The dependence of the uncertainty on measuring points number have been analyzed, and the recommendations for various fitting methods have been proposed in order to reduce the uncertainty.

The roundness deviation measurement with CMM

In the paper, the recommendations on the parameters of a circle measurement with CMM (Coordinate Measuring Machine) are described. The method of uncertainty estimation for the measured circle has been presented, too. The influence of the parameters of measured detail underwent discussion, like the type of form deviation and dimensional tolerances, as well as influence of the measurement method, particularly, number of probing points, CMM permissible error and fitting element type. The simulations and experimental measurement proved that the minimal number of probing points is not recommended. On the other hand, in the touch-trigger measurement, too large number of points does not increase the accuracy of measurement. As a result, the recommendations on the probe points number and CMM accuracy have been presented.

Analysis of CMM Accuracy in the Measurement of Roundness

In the paper, the possibility and accuracy of the roundness measurement with CMM (Coordinate Measuring Machines) has been analyzed. The accuracy of final measurement result is always affected by many factors and conditions of measurement. The following factors underwent discussion: the form deviation and tolerance of measured detail, and the measuring method determined by the number of measuring points, fitting element and uncertainty of CMM. The results of simulations and measurement have proved that the minimal number of measuring points (4 for circle measurement) is not enough. In order to achieve satisfactory results of the roundness measurement, the number of measuring points should be sufficiently increased. On the other hand, the unlimited increase of the points does not improve the measurements results, but extend the time of measurement. The recommendations on the number of measuring points and the required uncertainty of CMM have been presented, too.Copyright

Studies of Geometric Accuracy of Polygons Machined by Polygonal Turning Technique

In this paper, characterization of shape and dimensional accuracy of polygons manufactured by polygonal turning were investigated. The theoretical value of maximum value of outline error was calculated and compared with real sample shape deviation. The data obtained from geometrical measurement of manufactured samples, geometrical characteristics, allowed to evaluate the influence of cutting parameters on machined part accuracy.

Measurement of Surface Topography Using Computed Tomography

Computed tomography is a new field of coordinate measuring metrology. For this reason, many areas of its application are not yet completely known. The paper presents reproduction possibilities of geometrical structure of a surface by computer tomography. Results are combined with data from a classical tactile profilometer to measure surface topography. Comparison of the obtained values makes it possible to confirm the usefulness of computer tomography to reconstruct the surface geometry. This is especially important when indoor surfaces are indispensable. Such measurement with any other device than computer tomograph is not possible or requires damage of the element being measured. As a result of the measurement by means of a computer tomograph, from the same measurement data we obtain not only information about the surface and shape of the element, but also—as an additional advantage—ability to evaluate internal structure of material, for example its porosity or fibre distribution in case of composites.

Analysis of 3D printing parameters of gears for hybrid manufacturing

The paper deals with analysis and selection of parameters of rapid prototyping of gears by selective sintering of metal powders. Presented results show wide spectrum of application of RP systems in manufacturing processes of machine elements, basing on analysis of market in term of application of additive manufacturing technology in different sectors of industry. Considerable growth of these methods over the past years can be observed. The characteristic errors of printed model with respect to ideal one for each technique were pointed out. Special attention was paid to the method of preparation of numerical data CAD/STL/RP. Moreover the analysis of manufacturing processes of gear type elements was presented. The tested gears were modeled with different allowances for final machining and made by DMLS. Metallographic analysis and strength tests on prepared specimens were performed. The above mentioned analysis and tests were used to compare the real properties of material with the nominal ones. To improve the quality of surface after sintering the gears were subjected to final machining. The analysis of geometry of gears after hybrid manufacturing method was performed (fig.1). The manufacturing process was defined in a traditional way as well as with the aid of modern manufacturing techniques. Methodology and obtained results can be used for other machine elements than gears and constitutes the general theory of production processes in rapid prototyping methods as well as in designing and implementation of production.The paper deals with analysis and selection of parameters of rapid prototyping of gears by selective sintering of metal powders. Presented results show wide spectrum of application of RP systems in manufacturing processes of machine elements, basing on analysis of market in term of application of additive manufacturing technology in different sectors of industry. Considerable growth of these methods over the past years can be observed. The characteristic errors of printed model with respect to ideal one for each technique were pointed out. Special attention was paid to the method of preparation of numerical data CAD/STL/RP. Moreover the analysis of manufacturing processes of gear type elements was presented. The tested gears were modeled with different allowances for final machining and made by DMLS. Metallographic analysis and strength tests on prepared specimens were performed. The above mentioned analysis and tests were used to compare the real properties of material with the nominal ones. To improve t...

Piston assembly in the most powerful 2.0l diesel engine – case study of the current tribological system and innovative concepts for the future

This article is a contribution to the ongoing debate on the scenario of the vehicle powertrains development. The directions of the internal combustion engines development in search of the possibility of effective economic and ecological indicators improvement have been indicated. It has been pointed out that this goal can be achieved through the use of nanotechnology in order to exceed the downsizing barriers resulting from the permissible mechanical loads for conventional materials. The article presents the study of the construction and materials used in the piston assembly of the most advanced four-cylinder, compression-ignition diesel engine currently in manufacture. Original concepts of nanotechnology have been proposed to reduce friction losses in major friction components of future engines with extremely high loads. The main idea is to verify the hypothesis that the sub-micron surface texture of the friction components obtained in the process of applying anti-wear outer layers can lead to an effective reduction of friction losses under real engine operating conditions. Computer simulations of the effects of introducing the surface texture in the upper sealing ring on friction loss confirm this hypothesis by showing friction value being reduced by 3-4% relative to the standard ring profile. In the summary, further advanced technologies designed to effectively utilize the unique properties of carbon nanotubes have been described.

Topographic inspection as a method of weld joint diagnostic [Topografsko ispitivanje kao metoda za dijagnosticiranje stanja zavarenog spoja]

The paper demonstrates a topographic inspection in the specific context of three kinds of inspection methods of austenitic stainless steel welds. Visual and metrological inspection was analysed during tungsten inert gas (TIG) welding tests, showing the non-destructive techniques: X-ray, computed tomography, and surface profilometry. The article is a response to the lack of information, especially in the area of non-destructive techniques suitable for wide practical application. The Paper presents advantages and drawbacks of the analysed diagnostic methods and a classification of conventional and specific welded joint flaws. The most important defect in practical applications determining reliability of a welded joint is cracks. This kind of diagnostic is based on the obtained information about anisotropic and inhomogeneous volume under consideration in the heat-affected zone of a weld.

Topografsko ispitivanje kao metoda za dijagnosticiranje stanja zavarenog spoja

The paper demonstrates a topographic inspection in the specific context of three kinds of inspection methods of austenitic stainless steel welds. Visual and metrological inspection was analysed during tungsten inert gas (TIG) welding tests, showing the non-destructive techniques: X-ray, computed tomography, and surface profilometry. The article is a response to the lack of information, especially in the area of non-destructive techniques suitable for wide practical application. The Paper presents advantages and drawbacks of the analysed diagnostic methods and a classification of conventional and specific welded joint flaws. The most important defect in practical applications determining reliability of a welded joint is cracks. This kind of diagnostic is based on the obtained information about anisotropic and inhomogeneous volume under consideration in the heat-affected zone of a weld.