激光温喷丸TC4钛合金的阻尼特性研究

Study of TC4 Titanium Alloy Based on the Variation of Damping Properties Introduced by Warm Laser Peening

在不同表面温度下对TC4钛合金试样进行激光温喷丸实验,使用频率响应法测试TC4钛合金试样的一阶弯曲振动共振频率和阻尼比,测定了喷丸区域半高宽值(FWHM),研究在不同试样表面温度下激光喷丸对TC4钛合金阻尼特性的影响,分析激光温喷丸中试样表面温度与最终一阶弯曲振动阻尼比的关系,讨论了不同试样表面温度对试样阻尼性能的影响机制。结果表明:在进行激光温喷丸时,试样在动态应变时效温度下形成的高密度位错对阻尼特性有重要影响,随着试样表面温度的上升,试样处理后的一阶弯曲振动阻尼比不断升高,在表面温度达到350℃时试样最终处理后阻尼比达到最大值;与激光喷丸技术相比,TC4试件的阻尼比从2.1%提升到了3.2%,表明了激光温喷丸可以有效减小振动工况下的振动应力。

The experiments of warm laser peening on TC4 titanium alloy with different temperatures were carried out.The first-order vibration damping ratios of TC4 titanium alloy specimens were tested by using frequency response method.The FWHM values of the processed areas were tested.The effects of warm laser peening（WLP）with different treating temperatures on damping properties of TC4 titanium alloy were investigated by summarizing the relationship between the WLP temperatures and first-order vibration damping ratios of specimens.The mechanism of damping properties improvement on TC4 titanium alloy treated by WLP with different applied temperature was discussed.It is shown that high dislocation density obtained by WLP under dynamic strain aging temperature is a critical factor of damping properties improvement of TC4 titanium alloy.With the rising surface temperature,the first-order vibration damping ratios keep increasing and reach acme when the treating temperature is 350 ℃.Compared with laser peening,damping ratios of specimen treated by WLP increase from 2.1% to3.2%.Owing to this,the vibration stress is reduced.