Sheet metal forming belongs to one of the most important technologies enabling the production durable but quite lightweight metal parts. The quality of the drawn parts depends on the deformed sheet metal, applied forming technology and process parameters, such as contact pressure, relative velocity, temperature or lubrication. The forming of steel (1.4021) parts using benign lubricant is analysed. The paper proposes replacing conventional mineral/synthetic lubricants with ones based on vegetable oils and boric acid. The effectiveness of the lubricants was assessed in laboratory strip drawing and cupping tests, and in production. An oil-based lubricant with an additive of boric acid is very effective in reducing frictional resistance and protecting the forming tools against galling. Graphic

FSW (Friction Stir Welding) and RFSSW (Refill Friction Stir Spot Welding) joints have been increasingly used in industrial practice. They successfully replace fusion-welded, riveted or resistance-welded joints. In the last two decades, dynamic development of this method has stimulated investigations of the fast methods for joint diagnostics. These methods should be non-destructive and easy to be used in technological processes. The methods of assessment of joint quality are expected to detect discontinuities in the structures welded using FSW and FSSW methods. Reliable detection of flaws would substantially extend the range of applications of FSW joints across many sectors of industry, including aviation. The investigations carried out in this paper allowed for characterization of defects present in FSW and RFSSW joints. Causes of these defects were also stressed. An overview of the methodologies for assessment of joint quality was presented. Results of assessment of the quality of joints made of 2024T6 aluminium sheet metal using FSW and RFSSW method were presented.

The study presents an analysis of wear of tools made of 1.2344 steel and MP159 alloy for the process of obtaining an overlap joint in 1.0 mm and 0.8 mm sheet metal made of 7075 T6 aluminum alloy using friction stir welding (FSW) technology. Tool geometry was designed at the Czestochowa University of Technology. Evaluation of tool wear was conducted based on the measurements of geometry of working area of tools by means of a multisensory meter system and based on the assessment of the working area by means of a stereoscope after individual stages of wear tests. Furthermore, based on the results of a static tensile strength test and metallographic examinations of the specimens sampled from the joints obtained during tool wear tests, the effect of the degree of tool wear on joint quality was also evaluated. Analysis of the results revealed that both the tool made of 1.2344 steel and that made of MP159 alloy were substantially worn, increasing the risk of further use of the tools for the joint material (7075-T6) after obtaining the joint with length of 200m, which suggests their low durability. Furthermore, modification of tool geometry caused by wear led to insignificant improvements in joint strength. Therefore, the results of wear measurement set directions for further modification of tool geometry, also due to the fact that despite a substantial wear, the tools continued to yield high-quality joints without defects. As demonstrated in the study, the type of tool material does not only impact on tool life but also, as it was the case in their geometry, has a significant effect on the quality of obtained joints. Although the tool made of MP159 alloy was worn more than the tool made of 1.2344 steel, it allowed for obtaining the joints with substantially better strength parameters.