12 research outputs found
Application of the Computed Tomography to Control Parts Made on Additive Manufacturing Process
AbstractThe article presents possibilities of application computed tomography to study elements made with additive methods. 3D printing is currently growing very rapidly and already allows to execute ready-to-use, structurally complex elements consisting of one or more parts. Similarly, computed tomography (CT), as the youngest measurement technique and methods to control the geometrical size of the parts, allows to control through any element and evaluate both the quality of each individual components and their assembly.This technique is especially valuable for the evaluation of additive methods. What is more, the evaluation of porosity on the individual sections of the parts might be conducted. It is also possible to obtain information about the location and thickness of each of the outer wall and inaccessible by any other techniques of non-destructive quality control of construction elements filling the various parts of the printed parts
MJERENJE DEVIJACIJE KRUŽNOSTI NA KOORDINATNIM MJERNIM STROJEVIMA
In the article, the form deviation (roundness) measurement with the Coordinate Measuring Machine has been discussed. The influence of the measuring points number and the type of the roundness deviation on the result (since different fitting elements are used) has been presented. The obtained investigation results prove that a minimal number of points is not enough for measurement, while too large of a number does not improve the measurement, as well. A recommendation on the measuring points number has been given.U ovom Älanku razmatrano je mjerenje devijacije oblika (kružnosti) na koordinatnim mjernim strojevima. Prikazan je utjecaj broja mjernih toÄaka i tip devijacije kružnosti na rezultat. Dobiveni rezultati istraživanja dokazuju da minimalni broj toÄaka nije dovoljan za mjerenje, dok preveliki broj toÄaka ne poboljÅ”ava mjerenje. Dana je preporuka o broju mjernih toÄaka
Topographic inspection as a method of weld joint diagnostic
U radu se demonstrira topografsko ispitivanje u specifiÄnom kontekstu triju vrsta inspekcijskih metoda zavara od austenitnog nehrÄajuÄeg željeza. Vizualna i metroloÅ”ka kontrola provedena je tijekom ispitivanja zavarivanja TIG postupkom, primjenom ne-destruktivnih metoda: rendgensko ispitivanje, kompjuterizirana tomografija i profilometrija povrÅ”ine. Rad je reakcija na nedostatak informacija, posebice u podruÄju ne-destruktivnih metoda prikladnih za Å”iroku primjenu u praksi. U radu se prezentiraju prednosti i nedostaci analiziranih dijagnostiÄkih metoda i klasifikacija uobiÄajenih i specifiÄnih mana zavarenog spoja. Najvažnija neispravnost u praktiÄnim primjenama kod odreÄivanja pouzdanosti zavarenog spoja su pukotine. Ova vrsta dijagnoze zasnovana je na dobivenim podacima o promatranom anizotropskom i nehomogenom volumenu u dijelu zavara pod utjecajem topline.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
Characterization of 5356 Aluminum Walls Produced by Wire Arc Additive Manufacturing (WAAM)
Wire arc additive manufacturing (WAAM) is renowned for its high deposition rate, enabling the production of large parts. However, the process has challenges such as porosity formation, residual stresses, and cracking when manufacturing aluminum parts. This study focuses on ana-lyzing the porosity of AA5356 walls manufactured using the WAAM process with the Fronius cold metal transfer system (Wels, Austria). The walls were machined to obtain specimens for tensile testing. The study used computed tomography and the tensile test to analyze the specimensā porosity and its potential relation to tensile strength. The process parameters analyzed were travel speed, cooling time, and path strategy. In conclusion, increasing travel speed and cooling time significantly affects pore diameter due to the lower heat input to the weld zone. Porosity can be reduced when diminishing heat accumulation. The results indicate that an increase in travel speed produces a slight decrease in porosity. Specifically, the total pore volume diminishes from 0.42 to 0.36 mm3 when increasing the travel speed from 700 to 950 mm/min. The ultimate tensile strength and maximum elongation of the āback and forthā strategy are slightly higher than those of the āgoā strategy. After tensile testing, the ultimate tensile strength and yield strength did not show any relation to the porosity measured by computed tomography. The percentage of the pore total volume over the measured volume was lower than 0.12% for all the scanned specimens