Arc-PVD coatings for titanium machining tool

The paper presents results of life tests in machining titanium alloy with cutting carbide tool with Ti-Mo-Al-Ni-Si-N, (Ti, Al) N coatings and without it. Shown, that tool life with first coatings is 1.8 and 3.6 times higher than tool with second coatings and simple carbide tool,respectively.

The influence of cooling techniques on cutting forces and surface roughness during cryogenic machining of titanium alloys

Titanium alloys are one of the materials extensively used in the aerospace industry due to its excellent properties of high specific strength and corrosion resistance. On the other hand, they also present problems wherein titanium alloys are extremely difficult materials to machine. In addition, the cost associated with titanium machining is also high due to lower cutting velocities and shorter tool life. The main objective of this work is a comparison of different cooling techniques during cryogenic machining of titanium alloys. The analysis revealed that applied cooling technique has a significant influence on cutting force and surface roughness (Ra parameter) values. Furthermore, in all cases observed a positive influence of cryogenic machining on selected aspects after turning and milling of titanium alloys. This work can be also the starting point to the further research, related to the analysis of cutting forces and surface roughness during cryogenic machining of titanium alloys.

Progress in Titanium Machining

Milling and drilling of titanium alloys represent a key technology for the aircraft manufacturers. The balancing act between production costs and tool costs leads to the need of tests and an optimized setup of the whole process. A Styrian consortium with experts in materials, tools and machining has been formed to extend the tool life in machining of titanium alloys. A series of tests is set up to evaluate the roughing and finishing operations. For finishing operations ultrasonic assisted milling is introduced and compared with conventional milling. Force measurement and optical wear detection are used for tool characterization.

Sintered Nickel Casing for Irradiation Targets

The aim of this work was to develop an alternative way to obtain casings used with irradiation targets containing uranium, for the production of the radionuclide Mo-99-Tc99m. The targets used for the production of Mo-99 are materials containing U-235 designed to be irradiated in a nuclear reactor. Usually these targets are encapsulated in aluminum or stainless steel. The idea here is to obtain casings by encapsulating a uranium button or a metallic cylinder with compacted and sintered nickel powder, this serving as a sealing for the fissile products occurring during U-235 irradiation. The sintered high purity nickel powder samples were compacted in uniaxial hydraulic press at 195 MPa. The sintering of the samples was carried out in an open-air furnace in an atmosphere with a certain control using titanium-machining chips at 600 °C. The samples bulk density was evaluated by the Archimedes' principle. The porosity of 20.08% was measured by mercury porosimetry. The microstructure was investigated by scanning microscopy revealing interconnected porosity and nickel oxide at the particles boundary surface. The results obtained by sintering of nickel powder according to the experimental undertaken, indicate the feasibility of achieving a casing for uranium targets.