Influence of Workpiece Hardness on Tool Wear in Profile Micro-milling of Hardened Tool Steel

Machining of engineering metallic materials on micro-level is very complicated. Micro-milling with solid tools, as one of microengineering technologies, is an acceptable process to machining of complex metallic micro-parts. The main problem in micro-milling is sensitivity of cutting tool, due its suppleness and short tool life, and its influences to workpiece accuracy and quality. In this paper is experimentally investigated tool wear of micro-milling tool. During machining tests, influence of workpiece hardness and process parameters is evaluated. Workpiece was cold work alloyed tool steel X155CrVMo12, hardened to different hardness 45, 54 and 63 HRc. Cutting tool was carbide ball-end micro-mill with TiAlN coating, and diameter of 0.6 mm. For different combination of input parameters, tool wear curves is presented, and signification of input parameters on tool wear is evaluated and discussed

Towards a European quantum network

Already deployed optical fibers have been utilized to realize the first quantum network connecting three countries. The cities of Trieste (Italy), Rijeka (Croatia) and Ljubljana (Slovenia) have exchanged quantum keys with a rate up to 3.13 kps, realizing quantum key distribution in a real-world scenario

Tribology of Composite Materials and Coatings in Manufacturing

The chapter presents studies regarding the tribological performance of composite materials and multilayer composite coated tools in manufacturing processes carried out by the authors. Two manufacturing processes were investigated—metal forming and metal cutting. In metal forming, the study aimed to explore lubricant-free forming utilizing multilayer DLC composite hard coating as the potential tool coating. The experimental studies on the coating include characterization of the coating, and tribological analysis of the coating using commercially available pin-on-disk, laboratory tribology simulative test and industrial ironing of stainless steel. In order to examine the influence of temperature and contact pressure along the tool/workpiece interface on friction, Finite Element analysis was performed. Meanwhile, in metal cutting, two environmentally benign machining techniques were investigated to determine their potentials in delaying tool wear progression. First, sustainable machining by coupling multilayer ceramic composite coated-tool with cryogenic coolant as the cutting fluid. Second, the machining of Carbon Fibre Composite and Titanium alloys stacks using Ultrasonic Assisted Drilling (UAD) technique. Both techniques include investigations on machining conditions with varied cutting tool speeds. The examinations on the experimental results were focused on temperature, tool wear, surface integrity and metallurgical structure of near-surface region