Being easily fabricated, welded, biocompatible, having a high strength-to-weight ratio, withstanding comparatively high temperatures up to 800°C and low modulus of elasticity make grade titanium and its alloys an important choice for automotive, biomedical and aerospace industries. In contempt of the different pleasant assets of Ti-6Al-4V alloy, the operation of this alloy is restricted especially when it comes to tribological and surface morphological characteristics. Enhancing these properties is important, for this purpose, a diversity of attempts and studies have been conducted. This paper mounts a review of morphological and tribological behaviors of titanium alloys including Ti-6Al-4V against different materials counting with carbide tools and other types of materials under dry and lubricated sliding conditions. The surface morphological, wear, and other properties have been discussed in this review article.
Precision milling of free (curved) surfaces with the use of monolithic milling cutters is used in the production of hardened steel elements such as dies, molds, or press tools. Precision milling processes are carried out with the following milling parameters: axial cutting depth ap <0.3 mm, cutting width ae <0.5 mm and the required machining accuracy below 40 µm. The quality of the obtained surfaces in injection molds is directly transferred to the quality of the molded part. One of the key criteria for the manufactured elements is the surface quality which is mainly assessed by the roughness parameters. Due to the use of carbide tools high reliability and quality of machining is obtained which allows to eliminate the grinding process. In precision milling processes, due to the very small radius of the cutting edge and the cross-sections of the cutting layers, the conditions that must be met for the decohesion process to occur are fundamentally diff erent from macro-scale. The minimum value range of ap and ae parameters was determined in a carried-out experiment, which allows for stable and repeatable machining. The tests were carried out with double-edge shank cutters with a diameter of 6 mm on a workpiece made out of WCVL hardened steel 45–47 HRC. Recommended machining conditions have been defi ned to ensure the required technological quality of the surface layer. The research was fi nanced under the research project POIR.01.01.01-000890/17 co-fi nanced by the European Union from the European Regional Development Fund.
Wear of the working surfaces of the forging dies in the process of manufacturing products with the die forging technique leads to deterioration of their operational properties as well as their technological quality. A characteristic feature of production in small and medium-sized enterprises is the high variability of the product range and short production series, which can be repeated in the case of re-orders by customers. In this type of production conditions, a technological criterion in form of – a change in the characteristic and selected dimension of forging is usually used to assess the quality of products. An important problem is, whether by taking up another order for a series of the same type of product, it will be possible to implement it with the existing die, or should a new die be made? As a result of the research carried out in the company implementing this type of contract, a procedure was proposed for forecasting the abrasive wear of die working surfaces on the basis of a technological criterion, easy to determine in the conditions of small and medium-sized enterprises. The paper presents the results of the wear assessment of a die made out of hot-work tool steel X37CrMoV5-1 (WCL) and dies made of 42CrMo4 alloy structural steel with hardfacing working surfaces by F-818 wire. To determine and forecast the process of die wear, a mathematical model in the form of neural networks was used. Their task was to forecast the ratio of the increment in introduced wear intensity indicator to the number of forgings made during the process. Taking into account
The article presents tools, methods and systems used in mechanical engineering that in combination with information technologies create the grounds of Industry 4.0. The authors emphasize that mechanical engineering has always been the foundation of industrial activity, while information technology, the essential part of Industry 4.0, is its main source of innovation. The article discusses issues concerning product design, machining tools, machine tools and measurement systems.
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The paper presents results obtained from the destructive laboratory investigation conducted on materials from pressure vessels after long-term operation in the refinery industry. Tested materials contained structural defects, which arose from improper heat treatment during steel plate manufacturing. Detailed metallographic and chemical composition tests and static tensile tests were conducted. Next, complex tensile tests were conducted with simultaneous acoustic emission (AE) monitoring while observing microstructural changes by light microscopy. From the laboratory tests, the correlations between the AE signal parameters and material microstructural damage during the tensile tests were developed. The results will be used as a basis of new algorithms for the structural condition assessment of in-service pressure equipment.
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