Research On Precision Forming And Surface Treatment Of Titanium Leading Edge

Leading edges improve the seismic and wear resistance of composite blades. Traditional leadingedges made of stainless often separate from blades due to great centrifugal force and poor bondingproperties with composites, which leads to severe safety problems.The forming precision and surfacemorphology of leading edges are the major factors effect bonding properties of leadingedges/composite blades.TB8titanium alloy offers high strength, small density, and have a good compatibility withcomposites, which will be widely used in aeronautic and astronautic areas.Inthis paper, a pilot studyon the manufacture technology of TB8titanium leading edgeswas conducted:1) Thefactors which effect precision forming of TB8titanium leading edges were discussed.Uniaxial tensile testsand shot time stress relaxation tests of TB8alloy sheets have been taken atelevated temperature. The hot forming die was designed and optimized by numerical analysis;springback ofthe leading edge was probed at different temperature and reasonable forming processparameters were found.2) The titanium adherents werepretreated by different means like microarcoxidation,anodizingand laser texturing. Bonding properties of titanium adherents were compared atmany process parameters. The results showed that: The best shear strength was31MPa when thetitaniumsamples were treated at350V and with a frequency of400Hz. Bonding behaviors of titaniumtreated by chromic acid anodizing method and sodium hydroxide anodizingrespectively werecompared. The adherentsamples had greatest shear strength39.2MP by chromic acid anodizingtreatment at10V for15minutes and38.5MPa by sodium hydroxide anodizing treatment at10V for10min; The best bond strength was39.2MPa when the adherents were textured at70A with a pulsewidth2ms.