Machining of Hard Machine Materials

Import 22/07/2015Diplomová práce se zabývá návrhem a porovnáním dvou řezných geometrií vyměnitelných břitových destiček při soustružení těžkoobrobitelného materiálu Inconel 625 dle W. Nr. 2.4856. Teoretická část je zaměřena na charakteristiku a obrobitelnost těžkoobrobitelných materiálů a speciálních slitin. V praktické části práce se porovnává vliv řezné geometrie na průběh obrábění materiálu Inconel 625 čtvercovou a kruhovou břitovou destičkou. Experimentální testování bylo provedeno při podélném vnějším soustružení na CNC obráběcím soustruhu Mori Seiki NLX2500. Pro navržené břitové destičky byly v průběhu obrábění nastaveny konstantní řezné podmínky. V závislosti na změně hloubky řezu odebírané vrstvy materiálu bylo vyhodnoceno silové zatížení, zmapován průběh opotřebení VBD a změřena drsnost obrobeného povrchu. V závěru práce jsou vyhodnoceny naměřené hodnoty a proveden ekonomický rozbor jednotlivých vyměnitelných břitových destiček.This thesis present the design and comparison of two cutting geometries of indexable inserts for turning hard machining material Inconel 625 according to W. Nr. 2.4856. The theoretical part focuses on the characteristics and machinability hard materials and special alloys. The practical part compares the influence of cutting geometry square and round inserts in the machining Inconel 625. Experimental testing was conducted at the outer longitudinal turning on CNC machining lathe Mori Seiki NLX2500. For inserts were set constant cutting conditions. Depending on the depth of cut was evaluated force load, the wear inserts was mapped and measured the roughness of the machined surface. In conclusion, the measured values are evaluated and performed an economic analysis of the individual inserts.346 - Katedra obrábění, montáže a strojírenské metrologievýborn

Experimental investigation of cutting forces in high-feed milling of titanium alloy

Titanium super alloys are often used in the chemical and aerospace industries, especially because of financial savings. resulting primarily from cheaper operation of equipment. Machinability of titanium alloys is more difficult than that of other metals. In addition, the low thermal conductivity causes the alloy to stick to the cuffing edge of the cutting tool, thereby causing it to become dull faster. The article deals with the experimental evaluation of cutting forces and the design of suitable cutting parameters for the machining of the UNS R56260 titanium alloy with high-feed milling technology. Testing was carried out in climb and conventional milling under different cutting conditions. The cutting components of forces Fx, Fy, Fz were measured and evaluated. The results of the measurements were processed into a graphical form and suitable cutting conditions were designed in terms of the acting cutting forces.Web of Science141958

Impact of cutting tool geometry on the dynamic load of system in the machining process of nickel Alloy 625

The article is focussed on comparing and determining the impact of the cutting geometry of the cutting tool due to dynamic load on system and microgeometry machined surface. For longitudinal turning nickel alloy Alloy 625 (W. Nr. 2.4856) rounded indexable cutting insert was used (RCMT 10T3M0 - F2) and its equivalent squared indexable cutting insert (SNMG 120412 - MR3) coated with fine-grained PVD (Ti, Al) N + TiN. Experimental testing of nickel Alloy 625 was under predetermined cutting conditions. In the selected depth of the removed material of 0.5 mm and 1.5 mm was measured in the course of machining the size of the individual components of cutting forces.Web of Science1032312

Influence of scanning strategy parameters on residual stress in the SLM process according to the Bridge Curvature Method for AISI 316L stainless steel

The present paper deals with the investigation and comparison of the influence of scanning strategy on residual stress in the selective laser melting (SLM) process. For the purpose of the experiment, bridge geometry samples were printed by a 3D metal printer, which exhibited tension after cutting from the substrate, slightly bending the samples toward the laser melting direction. Samples were produced with the variation of process parameters and with a change in scanning strategy which plays a major role in stress generation. It was evaluated using the Bridge Curvature Method (BCM) and optical microscopy. At the end, a recommendation was made.Web of Science137art. no. 165

Copyright protection in additive manufacturing

Additive Manufacturing (AM) has been proven to be a significant development for production as well as become an attractive alternative manufacturing process compared with Subtractive Manufacturing (SM). This can be explained by the massive advantages of AM including mass customisation, less material wastage and ability to create prototypes. However, in order to make use of the AM process, firms, developers and designers require a virtual sharing platform, which can be used to trade designs and make the whole industry better off. This desire requires ways to protect the models and designs from digital thieves. Moreover, internal transactions of designs inside a single firm also require a significant level of security. So, this paper offers different ways of protecting both physical models and virtual designs. The solutions in this paper can be used to ensure the integrity of the physical products and virtual designs during different kinds of transactions.Web of Science20236526651

Eddy current testing of artificial defects in 316L stainless steel samples made by additive manufacturing technology

Additive manufacturing has many positives, but its incorporation into functional parts production is restricted by the presence of defects. Eddy current testing provides solutions for their identification; however, some methodology and measurement standards for AM (additive manufacturing) products are still missing. The main purpose of the experiment described within this article was to check the ability of eddy current testing to identify AM stainless steel parts and to examine the data obtained by eddy currents variation under the influence of various types of designed artificial defects. Experimental samples were designed and prepared with SLM (selective laser melting) technology. Artificial defects, included in the samples, were detected using the eddy current testing device, taking the important circumstances of this non-destructive method into account. The presented research shows significant potential for eddy current testing to identify defects in AM products, with a resolution of various types and sizes of defects. The obtained data output shows the importance of choosing the right measurement regime, excitation frequency and secondary parameters setup. Besides the eddy current testing conditions, defect properties also play a significant role, such as their shape, size, if they are filled with unmolten powder or if they reach the surface.Web of Science1519art. no. 678

Quality of surface texture and mechanical properties of PLA and PA-based material reinforced with carbon fibers manufactured by FDM and CFF 3D printing technologies

The paper presents the results of mechanical tests of models manufactured with two 3D printing technologies, FDM and CFF. Both technologies use PLA or PA-based materials reinforced with carbon fibers. The work includes both uniaxial tensile tests of the tested materials and metrological measurements of surfaces produced with two 3D printing technologies. The test results showed a significant influence of the type of technology on the strength of the models built and on the quality of the technological surface layer. After the analysis of the parameters of the primary profile, roughness and waviness, it can be clearly stated that the quality of the technological surface layer is much better for the models made with the CFF technology compared to the FDM technology. Furthermore, the tensile strength of the models manufactured of carbon fiber-enriched material is much higher for samples made with CFF technology compared to FDM.Web of Science1311art. no. 167

Topological optimization of the Formula Student bell crank

This paper focuses on the topological optimization of the Formula Student bell crank. Modern trends in designing are weight reduction, and due to this, also reduction of fuel consumption. Topological optimization allows modification of the shape of the component in respect to the strength demand and the boundary conditions of component loading. The topological optimization software with respect to computational methods is used. This software accomplishes several interactions and evaluates the optimal one. Topologically optimized component manufacturing is usually done by 3D printing. In this article, the authors follow the development of a topologically optimized bell crank, choice of printing material (metallic powder), and description of its design development and geometrical shape smoothing step by step - from the very first design to the final topologically optimized model. The design also takes into consideration the production technology by metallic powder 3D printing and post-processing, which cannot be realized without CNC machining and clamping jigs.Web of Science20192968296

Effects of equal channel angular pressing and heat treatments on the microstructures and mechanical properties of selective laser melted and cast AlSi10Mg alloys

This study investigated the impact of the equal channel angular pressing (ECAP) combined with heat treatments on the microstructure and mechanical properties of AlSi10Mg alloys fabricated via selective laser melting (SLM) and gravity casting. Special attention was directed towards determining the effect of post-fabrication heat treatments on the microstructural evolution of AlSi10Mg alloy fabricated using two different routes. Three initial alloy conditions were considered prior to ECAP deformation: (1) as-cast in solution treated (T4) condition, (2) SLM in T4 condition, (3) SLM subjected to low-temperature annealing. Light microscopy, transmission electron microscopy, X-ray diffraction line broadening analysis, and electron backscattered diffraction analysis were used to characterize the microstructures before and after ECAP. The results indicated that SLM followed by low-temperature annealing led to superior mechanical properties, relative to the two other conditions. Microscopic analyses revealed that the partial-cellular structure contributed to strong work hardening. This behavior enhanced the material's strength because of the enhanced accumulation of geometrically necessary dislocations during ECAP deformation.Web of Science213art. no. 9

Complex corrosion properties of AISI 316L steel prepared by 3D printing technology for possible implant applications

This paper deals with the investigation of complex corrosion properties of 3D printed AISI 316L steel and the influence of additional heat treatment on the resulting corrosion and mechanical parameters. There was an isotonic solution used for the simulation of the human body and a diluted sulfuric acid solution for the study of intergranular corrosion damage of the tested samples. There were significant microstructural changes found for each type of heat treatment at 650 and 1050 degrees C, which resulted in different corrosion properties of the tested samples. There were changes of corrosion potential, corrosion rate and polarization resistance found by the potentiodynamic polarization method. With regard to these results, the most appropriate heat treatment can be applied to applications with intended use in medicine.Web of Science137art. no. 152