SrSiAlN_3:Eu^(2+)/胶黏剂复合材料荧光的压应力传感特性

首次研究了红色宽带发光的SrSiAlN_3:Eu^(2+)荧光粉与胶黏剂组成复合材料后的力敏荧光特性,分析了样品形状和胶黏剂成分对复合材料压敏荧光特性的影响。荧光压应力传感实验系统由力加载装置与荧光发射光谱测试系统组成。实验结果表明SrSiAlN_3:Eu^(2+)荧光粉/胶黏剂复合材料的荧光特征参数"谱带重心"随压应力增大而蓝移,而荧光强度和谱峰频移均不表现出明显的压敏性。样品几何形状的差异不影响压应力传感灵敏度。谱带重心波长的力致移动具有可重复性,相应得到荧光粉/硅胶、荧光粉/H610应变胶两款复合材料的谱带重心波长移动应力传感的灵敏度分别为0.20 nm/MPa及0.31 nm/MPa,均较常规的红宝石荧光压谱系数高三个数量级以上,系统的分辨力达0.055 MPa。实验结果表明SrSiAlN_3:Eu^(2+)/胶黏剂复合材料是性能良好的光学无线应力传感敏感材料。

PIEZOSPECTROSCOPIC STUDY OF RESIDUAL STRESSES AROUND INDENTATIONS IN SiC/Al_O_3 NANOCOMPOSITE

A new experimental measurement of residual stresses around Vickers′ indentations on the surface of the SiC/Al 2O 3 nanocomposites is proposed with the aid of a Raman microprobe. Results s how that the shifts of R lines in the fluorescence spectra va ry with the distance from the centre of indentation. The magnitude of load appli ed on the surface of the materials through the indenter influences the shifts of R lines to great extent. The luminescence of R lines of the materials before indenting is used to determine the residual stresses around the indentation in the materials, assuming that the stress tensor is transversely isotropic. Final ly, the term of hydrostatic stress is adopted to explain and compare different residual stresses around indentations with the increase of the indenting load an d the distance from the centre of indentations. <