With the rapid advancement of 3D-printing technology, additive manufacturing using FDM extrusion has emerged as a prominent method in manufacturing. However, it encounters certain limitations, notably in surface quality and dimensional accuracy. Addressing issues related to stability and surface roughness necessitates the integration of 3D-printing technology with traditional machining, a strategy known as the hybrid technique. This paper presents a study of the surface geometric parameters and microstructure of plastic parts produced by FDM. Sleeve-shaped samples were 3D-printed from polyethylene terephthalate glycol material using variable layer heights of 0.1 mm and 0.2 mm and then subjected to the turning process with PVD-coated DCMT11T304 turning inserts using variable cutting parameters. The cutting depth was constant at 0.82 mm. Surface roughness values were correlated with the cutting tool feed rate and the printing layer height applied. The selected specimen’s microstructure was studied with a Zeiss EVO MA 15 scanning electron microscope. The roundness was measured with a Keyence VR-6200 3D optical profilometer. The research results confirmed that the additional application of turning, combined with a reduction in the feed rate (0.0506 mm/rev) and the height of the printed layer (0.1 mm), reduced the surface roughness of the sleeve (Ra = 1.94 μm) and increased its geometric accuracy.

At present peristaltic pumps are widely used in many branches of industry and national economy. Simplicity of construction, processability and possibility of pumping liquids with big quantity of solid particles are the main advantages while using peristaltic pumps. Therefore development of...

The prerequisite of the weld bead finishing is intricately linked to the quality of the welded joint. It constitutes the final, yet pivotal, stage in its formation, significantly influencing the reliability of structural components and machines. This article delineates an innovative post-weld surface finishing method, distinguished by the movement of a specialized cutting tool along a butt weld. This method stands out due to its singular approach to machining allowance, wherein the weld bead height is considered and eradicated in a single pass of the cutting tool. Test samples were made of AISI 304L, AISI 316L stainless steels and EN AW-5058 H321, EN AW-7075 T651 aluminum alloys butt-welded with TIG methods. Following the welding process, the weld bead was finished in accordance with the innovative method to flush the bead and the base metal’s surface. For the quality control of welded joints before and after the weld finishing, two non-destructive testing methods were chosen: Penetrant Testing (PT) and Radiographic Testing (RT). This article provides results from the examination of 2D profile parameters and 3D stereometric characteristics of surface roughness using the optical method. Additionally, metallographic results are presented to assess changes in the microstructure, the microhardness, and the degree of hardening within the surface layer induced by the application of the innovative post-weld finishing method.

The scheme of the cooling system is considered, which can be the basis for creating the most efficient cooling systems for IC engines of any purpose. It is assumed that the use of any other scheme is devoid of a rational basis. The scheme consists of two connected circulation circuits, in one of...

The maintenance properties of machine parts rely on a system of surface quality parameters, including geometrical, mechanical properties, and surface structure. This study examines how corrosion properties - a critical aspect of maintenance - depend on key surface quality parameters of butt-welded joints post-finishing. The research compares traditional grinding with an innovative post-weld finishing method. Corrosion results from material thermodynamic instability during manufacturing; over time, materials tend toward a more stable oxidized state. Welded joints pose significant corrosion fatigue challenges due to their structural complexity, material heterogeneity, and stress concentration, underscoring the study's importance. Test samples of AISI 304 L, AISI 316 L, EN AW-5058 H321, and EN AW-7075 T651 were butt-welded and finished with both methods. Surface morphology and roughness were characterized using a Zeiss Smart Zoom 5 digital microscope and an Alicona Infinite Focus G6 optical profilometer, enabling both 2D and 3D topographic analysis. Residual stresses were measured using the ProtoiXRD Combo X-ray diffractometer, and microhardness was determined with a NEXUS 4303 Vickers tester. Metallographic investigations were carried out using light and scanning electron microscopy. Electrochemical corrosion testing was conducted in 3.5% NaCl solution at 20 °C using a three-electrode system and an Autolab PGSTAT 302 N potentiostat. Tafel curve extrapolation, conducted via NOVA2 software, was used to calculate corrosion potential (E_corr) and current density (I_corr). Results showed that the innovative finishing method improves surface uniformity and reduces tensile residual stresses, leading to enhanced corrosion resistance, particularly in stainless steel specimens. The findings demonstrate that post-weld surface condition plays a key role in controlling corrosion behavior and confirm the effectiveness of the proposed finishing method in improving the integrity and longevity of welded joints.

The most common method of post-weld finishing is grinding with an abrasive tool. This finishing method leads to the occurrence of faults on the treated surface: locations missed or hardened twice, structural notches and stretching residual stress in the surface layer. The faults mentioned lead to the creation and development of ordinary as well as fatigue cracks, seizing or other damage. In addition, grinding is a process that often involves manual labour, which significantly increases the time required for finishing the procedure. Moreover, it is impossible to automate this process. Also, grinding is a process that is damaging for both people and the environment. In contrast to grinding and other processes of post-weld surface finishing, the innovative method, which is the subject of this article, does not have the faults and inconveniences of the previously mentioned techniques. The post-weld surface finishing method by moving of the innovative multi-edge cutting tool along the weld bead is presented in this article. In this method, machining allowance is treated as the weld bead height, which is flush-removed with the base material in one step during one pass of the cutting tool. The adjacent teeth height of changing and increasing according to the direction of feed and the difference in height between the first and last teeth are equal to the weld bead height. The number of cutting teeth necessary to flush-finish the weld bead with the base metal surface depends on the difference in the first and last teeth height and how it is divided. The tooth length is greater than half of the distance between the adjacent cutting teeth, which enables finishing the heterogeneous post-weld surface with many defects and increased hardness. The innovative method is characterised by short machining time of the weld bead and provides an accurate, efficient and economical process.