Study in dimension precision of micro straight thin wall with Ti-6Al-4V titanium alloy under mesoscale

During high-speed machining, the vibration will result in poor workpiece surface and damage the cutting tool as well as the machine tool. It will limit the productivity and lower the quality of thin-wall titanium alloy components. Moreover, vibration occurrence is strongly affected by the dynamic response of the whole system, particularly the stiffness of workpiece-fixture system. Improper fixture layout is prone to generate vibration, especially for the flexible workpiece. Hence, it’s necessary to suppress the vibration and improve the fixture design. In this work, a finite element model of the workpiece-fixture system is built. Based on this model, the laws of the natural frequency and vibration modals under different fixturing methods are obtained, which can be used to refine fixture design. With several additional auxiliary supports, the stiffness of the workpiece-fixture system is improved and the result showed that, the natural frequencies of thin-wall titanium alloy components can be improved to a level which is too high to be reached by tool’s excitation. The result of this study is helpful to design the optimum fixture scheme of thin-wall titanium alloy components.

Download Full-text

Investigating the Effect of Wire Feed Rate and Wire Tension on the Corner and Profile Accuracies During Wire-EDM of Ti-6Al-4V

Volume 4: Processes ◽

10.1115/msec2018-6540 ◽

2018 ◽

Author(s):

Roan M. Kirwin ◽

MD Rashef Mahbub ◽

Muhammad P. Jahan

Keyword(s):

Titanium Alloy ◽

Feed Rate ◽

Turbine Blades ◽

Thin Wall ◽

Wire Edm ◽

Machining Processes ◽

Wire Tension ◽

Thick Part ◽

Target Values ◽

Wire Feed

Ti-6Al-4V (grade 5 titanium alloy) is one of the most widely used materials in aerospace applications including turbine blades for aerospace engines. Due to the difficulty of machining titanium alloys using conventional machining processes, wire-electro-discharge machining (wire-EDM) is used extensively for cutting titanium parts with complex geometries and profiles. The objective of this study is to investigate the effect of two important non-electrical parameters in wire-EDM, i.e. wire feed rate and wire tension, on the geometric corner and profile accuracies of the Ti-6Al-4V parts machined by wire EDM. A complex profile was designed for machining in two different thicknesses of titanium alloy using each set of experimental parameters. The complex part includes corners with 45°, 90° and 112.5°, as well as thin wall section for measuring the kerf accuracy. It was found that with the increase of wire tension, the corner accuracies at almost all the angles improved. however, too high wire tension caused inaccuracies by providing larger angles than the target values. The effect of wire tension was dependent on the thickness of the machined part. For thinner workpiece the results of the angles generated barely followed a trend, whereas for thicker part, the measured angles followed an excellent trend. The kerf accuracies were found to improve with the increase of wire tension for thin part, whereas for thick part the results of kerf width accuracies were inconsistent. In case of wire feed rate, it was found that comparatively lower settings of wire feed rates were favorable for machining thinner parts with enhanced corner accuracies. On the other hand, slightly higher wire feed rates provided better corner accuracies for thick part. Besides corner inaccuracy, profile undercuts and deviations from the machining paths were observed for lower wire tensions. Finally, it can be concluded that comparatively lower wire feed rate and higher wire tension provides improved corner and profile accuracies. however, for machining thinner sections using wire-EDM, the trends are not obvious.

Download Full-text

Experimental investigation of laser shock peening on TC17 titanium alloy for thin-wall workpieces

Tenth International Conference on Information Optics and Photonics ◽

10.1117/12.2505912 ◽

2018 ◽

Author(s):

Boyu Sun ◽

Hongchao Qiao ◽

Jibin Zhao ◽

Ying Lu

Keyword(s):

Experimental Investigation ◽

Titanium Alloy ◽

Laser Shock Peening ◽

Thin Wall ◽

Laser Shock ◽

Shock Peening

Download Full-text

Chip Formation of Highly Efficient Cutting Titanium Alloy Membrane Disk

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.33.549 ◽

2010 ◽

Vol 33 ◽

pp. 549-554

Author(s):

Shu Cai Yang ◽

Min Li Zheng ◽

Yi Hang Fan

Keyword(s):

Titanium Alloy ◽

Cutting Force ◽

Chip Formation ◽

Fem Analysis ◽

Cutting Conditions ◽

Machining Process ◽

Thin Wall ◽

Variable Cross ◽

Serrated Chip ◽

Membrane Disk

Titanium alloy membrane disk is a typical part in aerial engine and it belongs to variable cross-section thin-wall part, which is apt to change its nature and difficult to machine. Serrated chip is prone to create in the machining process. A periodic serrated chip will cause high frequency undulation of the cutting force, and further leads to the cutting tool wear and affect the surface’s integrity. Based on the turning of titanium membrane disk, this paper used metallographic microscope and SEM to observe the morphology and micro shape of the chip, and analyzed the influence of cutting conditions on chip formation and the reason for serrated chip. Finally, a FEM analysis on the chip formation process is completed. Analysis results show that under all the set cutting conditions the serrated chip was formed in the machining process. The shearing slippage and fracture caused by dislocation movement can better explain the formation mechanism of serrated chip. The feed rate has great effect on the chip formation and the forming frequency of serrated chip. The FEM analysis results primly consistent with the experiment results, which can accurately forecast the cutting force, the distribution of temperature and the surface quality.

Download Full-text