The article presents the results of the analysis of the interactions between the single point incremental forming (SPIF) process parameters and the main roughness parameters of stiffened ribs fabricated in Alclad aluminium alloy panels. EN AW-7075-T6 and EN AW-2024-T3 Alclad aluminium alloy sheets were used as the research material. Panels with longitudinal ribs were produced with different values of incremental vertical step size and tool rotational speed. Alclad is formed of high-purity aluminium surface layers metallurgically bonded to aluminium alloy core material. The quality of the surface roughness and unbroken Alclad are key problems in SPIF of Alclad sheets destined for aerospace applications. The interactions between the SPIF process parameters and the main roughness parameters of the stiffened ribs were determined. The influence of forming parameters on average roughness Sa and the 10-point peak–valley surface roughness Sz was determined using artificial neural networks. The greater the value of the incremental vertical step size, the more prominent the ridges found in the inner surface of stiffened ribs, especially in the case of both Alclad aluminium alloy sheets. The predictive models of ANNs for the Sa and the Sz were characterised by performance measures with R² values lying between 0.657 and 0.979. A different character of change in surface roughness was found for sheets covered with and not covered with a soft layer of technically pure aluminium. In the case of Alclad sheets, increasing the value of the incremental vertical step size increases the value of the surface roughness parameters Sa and Sz. In the case of the sheets not covered by Alclad, reduction of the tool rotational speed increases the Sz parameter and decreases the Sa parameter. An obvious increase in the Sz parameter was observed with an increase in the incremental vertical step size.

The article presents the preliminary results of a research aimed at preparation for the extraction of chemical ammunition immersed after the Second World War(WWII) in the waters of the Baltic Sea (BS). It has been 70 years since the first steps aiming at elimination of mainly German chemical weapons were taken, while the expected durability (tightness) of metal barrels construction or other containers was estimated at 50-60 years. Consequently there is a serious risk of contamination of the Baltic Sea waters, not only with toxic warfare agents but also with the products of their decomposition. The evaluation of barrels’ and containers’ with TWA corrosion processes progress will determine the possibility of these munitions extraction to the surface in order to perform their classic utilization.

In this paper the passive layer cracking process that occurs under tensile stresses and anodic polarization conditions on AA1050, AA5052, AA5056, and AA7005 aluminum alloys was examined by means of direct current (dc) technique, dynamic electrochemical impedance spectroscopy (DEIS), and acoustic emission (AE). Research revealed the advantage of DEIS and AE methods over the dc one. It was also possible to determine the exact moment of the passive layer cracking on investigated aluminum alloys.

Studying roughness parameters and the topography of stiffening ribs in composite sandwich structures is important for understanding these materials’ surface quality and mechanical properties. The roughness parameters describe the micro-geometry of the surface, including the average height deviation, roughness depth, and waviness. The topography of the surface refers to the spatial arrangement and distribution of features such as bumps, ridges, and valleys. The study investigated the roughness parameters under three scenarios based on two SPIF process parameters: tool rotational speed(N) and feed rate (f). The vertical step was held constant at 0.4 mm across all scenarios. In scenario A, the process parameters were set at f = 300 mm/min and n = 300 rpm; in scenario B, f = 1500 mm/min and n = 3000 rpm; and in scenario C, f = 1500 mm/min and n = 300 rpm. The experimental research topography analyses revealed that the surface roughness of the stiffened ribs was highly dependent on the SPIF process parameters. The highest feed rate and tool rotational speed produced the smoothest surface texture with the lowest maximum height (Sz) value. In contrast, the lowest feed rate and tool rotational speed resulted in a rougher surface texture with a higher maximum height (Sz) value. Furthermore, the contour plots generated from the topography analyses provided a good visual representation of the surface texture and roughness, allowing for a more comprehensive analysis of the SPIF process parameters. This study emphasizes optimizing the SPIF process parameters to achieve the desired surface quality and texture of stiffened ribs formed in Litecor^® panel sheets.