为了提升电火花线切割(Wire cut Electric Discharge Machining,WEDM)加工后的TC4钛合金表面质量,减少表面重熔层厚度,采用不同浓度配比(1∶4、1∶6和1∶8)的HF-HNO_(3)酸蚀溶液对钛合金试件进行化学抛光处理。实验结果表明,HF-HNO_(3)...为了提升电火花线切割(Wire cut Electric Discharge Machining,WEDM)加工后的TC4钛合金表面质量,减少表面重熔层厚度,采用不同浓度配比(1∶4、1∶6和1∶8)的HF-HNO_(3)酸蚀溶液对钛合金试件进行化学抛光处理。实验结果表明,HF-HNO_(3)酸蚀溶液能使钛合金重熔层得到显著去除,表面微裂纹得到有效控制;当HF-HNO_(3)酸蚀溶液的浓度配比为1:6时,试件能获得最低的表面粗糙度和最大的表面粗糙度下降率,并且抛光前后钛合金表面元素含量发生了不同程度的变化,Ti、Al和V元素质量分数分别提高了21.5%、41.3%和13.2%,而O、C元素质量分数分别降低了82.5%和33.6%;HF-HNO_(3)酸蚀溶液可显著改善TC4钛合金试件电火花线切割加工后的表面缺陷。钛合金重熔层结构的主要成分与化学抛光后氧化膜的主要成分相似,但与氧化膜的结构不同,这对TC4钛合金试件表面质量提升具有重要意义。展开更多
The etch characteristics of Si_1-xGex films in HNO3:H2O:HF were examined. The etch rate ratio (etch selectivity) between Si_1-xGex and Si escalated with the growth of HNO3 concentration at low concentration level, and...The etch characteristics of Si_1-xGex films in HNO3:H2O:HF were examined. The etch rate ratio (etch selectivity) between Si_1-xGex and Si escalated with the growth of HNO3 concentration at low concentration level, and when the HNO3 concentration exceeded a critical level the etch selectivity descended with higher HNO3 concentration. The dependence of etch selectivity on the HNO3 concentration was due to the higher critical HNO3 concentration for etching Si than that for etching Si1-xGex. Since the Ge-Ge bond energy was weaker than that of Si-Si and Si-Ge, the Ge atoms were oxidized preferentially once the HNO3 composition exceeded the critical concentration of etching Si1-xGex,which was manifested by the XPS spectra of Si1-xGex etched in HNO3:H2O:HF. When the HNO3 volume rose to another critical value, the significant growth of the Si etch rate low-ered the etch selectivity. Although both the etch rates of Si1-xGex and Si dropped with lower HF concentration, the etch rate ra-tio of Si1-xGex to Si boosted remarkably due to the water-soluble characteristics of GeO2.展开更多
文摘为了提升电火花线切割(Wire cut Electric Discharge Machining,WEDM)加工后的TC4钛合金表面质量,减少表面重熔层厚度,采用不同浓度配比(1∶4、1∶6和1∶8)的HF-HNO_(3)酸蚀溶液对钛合金试件进行化学抛光处理。实验结果表明,HF-HNO_(3)酸蚀溶液能使钛合金重熔层得到显著去除,表面微裂纹得到有效控制;当HF-HNO_(3)酸蚀溶液的浓度配比为1:6时,试件能获得最低的表面粗糙度和最大的表面粗糙度下降率,并且抛光前后钛合金表面元素含量发生了不同程度的变化,Ti、Al和V元素质量分数分别提高了21.5%、41.3%和13.2%,而O、C元素质量分数分别降低了82.5%和33.6%;HF-HNO_(3)酸蚀溶液可显著改善TC4钛合金试件电火花线切割加工后的表面缺陷。钛合金重熔层结构的主要成分与化学抛光后氧化膜的主要成分相似,但与氧化膜的结构不同,这对TC4钛合金试件表面质量提升具有重要意义。
基金supported by the National Natural Science Foundation of China (Grant No. 61006088)the National Basic Research Program of China (973 Program) (Grant No. 2010CB832906)the Natural Sci-ence Foundation of Shanghai (Grant No. 10ZR1436100)
文摘The etch characteristics of Si_1-xGex films in HNO3:H2O:HF were examined. The etch rate ratio (etch selectivity) between Si_1-xGex and Si escalated with the growth of HNO3 concentration at low concentration level, and when the HNO3 concentration exceeded a critical level the etch selectivity descended with higher HNO3 concentration. The dependence of etch selectivity on the HNO3 concentration was due to the higher critical HNO3 concentration for etching Si than that for etching Si1-xGex. Since the Ge-Ge bond energy was weaker than that of Si-Si and Si-Ge, the Ge atoms were oxidized preferentially once the HNO3 composition exceeded the critical concentration of etching Si1-xGex,which was manifested by the XPS spectra of Si1-xGex etched in HNO3:H2O:HF. When the HNO3 volume rose to another critical value, the significant growth of the Si etch rate low-ered the etch selectivity. Although both the etch rates of Si1-xGex and Si dropped with lower HF concentration, the etch rate ra-tio of Si1-xGex to Si boosted remarkably due to the water-soluble characteristics of GeO2.
