Flow Field Simulation And Experimental Investigation On Macro Electrolyte Jet Electrochemical Turning of TB6 Titanium Alloy

Electrolyte jet electrochemical turning is an effective method to realize high-quality machining of titanium alloy rotating components; however, minimal research has been carried out in this field. This is because it is difficult to control the machining flow field, which leads to poor machining surface quality. In this work, numerical simulations were used to optimize the machining flow field and reduce the proportion of gas that mixed into the machining area. This can promote participation of the tool electrode tip in the electrochemical reaction and improve the machining efficiency. The effectiveness of the optimized machining flow field for jet electrochemical turning was verified experimentally. The results showed that all three kinds of revolving TB6 titanium alloy samples with different structures could maintain the original contour shape, with a contour error <1% and a machined surface roughness reaching Ra 2.414 μm. The results demonstrate the application potential of the jet electrochemical turning process.

Understanding the Role of β Recrystallization on β Microtexture Evolution in Hot Processing of a Near-β Titanium Alloy (Ti-10V-2Fe-3Al)

The present study evaluated the β recrystallization behavior and deformation microtexture evolution of TB6 titanium alloy (Ti-10V-2Fe-3Al) taking place during isothermal compression. The hot deformation tests were carried out in the temperature range below the β phase transition temperature and spanned a wide strain rate range of 0.0001~1 s−1. Microstructure evolution on β phase, including its recrystallization behavior and microtexture formation, is sensitive to the strain rates, whereas the average grain size of equiaxed α phase exhibits a slight increase with the strain rate decreasing. Moreover, β recrystallization is not homogeneous among the prior β grains, and is characterized by: (I) enriched β sub-grains, (II) sporadically or chain-like distributed recrystallized β grains with a grain size far less than the prior β grains, and (III) wave-shaped β grain boundaries. The β recrystallization is inadequate and its orientation takes on the inheritance characteristic, which makes the β microtexture significant after deformation. At a lower strain rate, the high activity of the {11−2}<111> and {12−3}<111> slip systems induced the crystal rotation around <101>, but such crystal rotation did not destroy the Burgers orientation relationship (BOR), which could be accounted for by the generation of a strong microtexture of <001>//RD. The divergences on β recrystallization fraction, the operation of slip systems, and initial crystal orientations explain the different microtexture components with varied intensities under different deformation conditions.

Influence of Wear and Tool Geometry on the Chatter, Cutting Force, and Surface Integrity of TB6 Titanium Alloy with Solid Carbide Cutters of Different Geometry

In this paper, vibration-free milling cutters (variable helix (VH) and variable pitch (VP) end mills) and standard (SD) end mills are used to machine TB6 (Ti-10V-2Fe-3Al) titanium alloy in order to study the influence of wear and geometric structure parameters of milling cutters on chatter, cutting force and surface integrity of machined surfaces. The results of the tests show that the wear of milling cutters has a significant influence on the chatter, cutting force, roughness, residual stress, and microhardness. Geometric structure parameters of milling cutters also have a clear impact on both chatter and cutting force. Also, chatter and cutting force have significant effects on roughness and residual stress, which are in turn affected by tool geometric structure parameters, separately.

Sheet cathode design and experimental study on the electrochemical machining of deep narrow slots in TB6 titanium alloy

TB6 titanium alloy is extensively applied in lightweight vehicles, biomedicine, and other domains because of its high specific strength, excellent fracture toughness, and excellent corrosion resistance. Electrochemical machining is a non-contact processing technology that has significant advantages in processing materials that are difficult to cut, such as cemented carbide, high-temperature alloys, and titanium alloys. To improve the consistency of deep narrow slots fabricated in TB6 titanium alloy via electrochemical machining, a sheet cathode design and experimental studies were carried out in this work. Based on a unidirectional fluid–structure coupling simulation, the influence of the stiffener arrangement on the cathode rigidity and flow-velocity distribution was studied. Furthermore, by modifying the geometry of the stiffener, the cathode deformation was significantly reduced, and flow-velocity uniformity at the cathode outlet was improved. The influence of a superimposed low-frequency oscillation on the gap distribution and the profile error of a deep narrow slot was investigated experimentally. The results revealed that when an applied voltage of 24 V, an oscillation frequency of 50 Hz, and an amplitude of 0.05 mm were adopted, a highly homogeneous deep narrow slot with an entrance gap of 0.24 mm and a side gap of 0.33 mm was machined into the TB6 titanium alloy.