XRD的TA10钛合金热压缩变形后位错演化分析

Dislocation evolution analysis of hot compressively deformed TA10 titanium alloy based on XRD

为了分析TA10钛合金位错演化,对TA10钛合金做了热模拟压缩实验,并对压缩后的试样进行了X射线衍射(XRD)实验。根据不同晶面的衍射峰,结合Dunn公式计算出了各晶面的位错密度。结果表明:TA10钛合金的软化机制在相变点以下以动态再结晶为主,相变点以上以动态回复为主;位错类型主要是柱面(1010),基面(0002)和锥面(1011)型位错; 800℃~900℃时,基面的位错密度变化最为显著,随着变形温度的升高,基面受动态再结晶的影响最大;应变速率增大及变形温度降低时总位错密度变大。随着变形量的增大,相变点以下,总位错密度先增大后减小,1 000℃时,总位错密度波动不大。使用XRD法可方便定量分析TA10钛合金热压缩变形后位错密度的演变规律。

Hot compression tests of TA10 titanium alloy are conducted to analyze the dislocation evolution of this type of alloy,and X-ray diffraction experiment is conducted on the samples after compression.According to the diffraction peaks of different crystal faces,the dislocation density of each crystal face is calculated in combination with the Dunn formula.Results show that the main softening mechanism of the TA10 titanium alloy is dynamic recrystallization below the phase transformation point,which turns into dynamic recovery above the phase transformation point.The primary dislocations consist of column plane(101 0),basal plane(0002),and conical plane(101 1)for deformed TA10 titanium alloy.At 800℃~900℃,the dislocation density of the basal plane changes most prominently,and the dynamic recrystallization has the strongest influence on the base surface dislocation when the temperature increases.The total dislocation density grows with the increase of strain rate and decrease of deformation temperature.With the increase of deformation,the total dislocation density rises first and then diminishes below the phase transformation point but is nearly unchanged at 1 000℃with the increase of deformation degree.The XRD method can be used to quantitatively analyze the evolution of dislocation density after hot compression deformation of TA10 titanium alloy.