Laser-weldable Sip-SiCp/Al hybrid composites with high volume fraction （60%-65%） of SiC reinforcement were fabricated by compression moulding and vacuum gas pressure infiltration technology. Microscopic observation ...Laser-weldable Sip-SiCp/Al hybrid composites with high volume fraction （60%-65%） of SiC reinforcement were fabricated by compression moulding and vacuum gas pressure infiltration technology. Microscopic observation displayed that the Sip-SiCp/Al hybrid composites with bilayer structure were compact without gas pores and the intergradation between Sip/Al layer and SiCp/Al layer was homogeneous and continuous. Further investigation revealed that the Sip-SiCp/Al hybrid composites possessed low density （2.96 g/cm^3）, high gas tightness （1.0 mPa·cm^3）/s）, excellent thermal management function as a result of high thermal conductivity （194 W/（m·K） and low coefficient of thermal expansion （7.0×10^-6 K-1）. Additionally, Sip-SiCp/Al hybrid composites had outstanding laser welding adaptability, which is significantly important for electronic packaging applications. The gas tightness of components after laser welding （48 mPa·cm^3）/s） can well match the requirement of advanced electronic packaging. Several kinds of these precision components passed tests and were put into production.展开更多
The three host glasses doped with Yb 3+ were prepared by means of conventional melt quenching technology, and the influence on physical and spectral properties of phosphate glass due to addition of B2O3 was investigat...The three host glasses doped with Yb 3+ were prepared by means of conventional melt quenching technology, and the influence on physical and spectral properties of phosphate glass due to addition of B2O3 was investigated and compared with silicate glass. The results show that due to the existence of OH- impurities which induce the non-radiative route, the fluorescence lifetime of phosphate glass is shorter, so silicate glass has better spectral properties than phosphate glass. Silicate glass has more excellent thermal-mechanical properties than phosphate glass, but with the addition of B2O3, thermal-mechanical properties of phosphate glass are improved greatly without fluorescence quenching effect, and this kind of borophosphate glass will be the candidate to be used in high average power solid state laser.展开更多
The effect of laser shock processing(LSP) on the hardness, surface morphology, residual stress, and thermal fatigue properties of a ZCuAl10Fe3Mn2 alloy was investigated to improve the thermal fatigue performance and d...The effect of laser shock processing(LSP) on the hardness, surface morphology, residual stress, and thermal fatigue properties of a ZCuAl10Fe3Mn2 alloy was investigated to improve the thermal fatigue performance and decrease the surface crack of high-temperature components. The microstructure and crack morphology were analyzed by scanning electron microscopy(SEM) and energy dispersive spectroscopy(EDS). The results showed that laser shock could significantly improve the thermal fatigue performance of the alloy at a pulse energy of 4 J. Under the effect of thermal stress and alternating stress, microstructure around the specimen notch was oxidized and became porous, leading to the formation of multiple micro-cracks. The micro-cracks in the vertical direction became the main cracks, which mainly expanded with the conjoining of contiguous voids at the crack tip front. Micro-cracks in other directions grew along the grain boundaries and led to material shedding.展开更多
文摘Laser-weldable Sip-SiCp/Al hybrid composites with high volume fraction （60%-65%） of SiC reinforcement were fabricated by compression moulding and vacuum gas pressure infiltration technology. Microscopic observation displayed that the Sip-SiCp/Al hybrid composites with bilayer structure were compact without gas pores and the intergradation between Sip/Al layer and SiCp/Al layer was homogeneous and continuous. Further investigation revealed that the Sip-SiCp/Al hybrid composites possessed low density （2.96 g/cm^3）, high gas tightness （1.0 mPa·cm^3）/s）, excellent thermal management function as a result of high thermal conductivity （194 W/（m·K） and low coefficient of thermal expansion （7.0×10^-6 K-1）. Additionally, Sip-SiCp/Al hybrid composites had outstanding laser welding adaptability, which is significantly important for electronic packaging applications. The gas tightness of components after laser welding （48 mPa·cm^3）/s） can well match the requirement of advanced electronic packaging. Several kinds of these precision components passed tests and were put into production.
文摘The three host glasses doped with Yb 3+ were prepared by means of conventional melt quenching technology, and the influence on physical and spectral properties of phosphate glass due to addition of B2O3 was investigated and compared with silicate glass. The results show that due to the existence of OH- impurities which induce the non-radiative route, the fluorescence lifetime of phosphate glass is shorter, so silicate glass has better spectral properties than phosphate glass. Silicate glass has more excellent thermal-mechanical properties than phosphate glass, but with the addition of B2O3, thermal-mechanical properties of phosphate glass are improved greatly without fluorescence quenching effect, and this kind of borophosphate glass will be the candidate to be used in high average power solid state laser.
基金financial supports from the National Natural Science Foundation of China—Youth Project (51801076)the Provincial Colleges and Universities Natural Science Research Project of Jiangsu Province (18KJB430009),China+1 种基金the Postdoctoral Research Support Project of Jiangsu Province (1601055C),Chinathe Senior Talents Research Startup of Jiangsu University (14JDG126),China。
文摘The effect of laser shock processing(LSP) on the hardness, surface morphology, residual stress, and thermal fatigue properties of a ZCuAl10Fe3Mn2 alloy was investigated to improve the thermal fatigue performance and decrease the surface crack of high-temperature components. The microstructure and crack morphology were analyzed by scanning electron microscopy(SEM) and energy dispersive spectroscopy(EDS). The results showed that laser shock could significantly improve the thermal fatigue performance of the alloy at a pulse energy of 4 J. Under the effect of thermal stress and alternating stress, microstructure around the specimen notch was oxidized and became porous, leading to the formation of multiple micro-cracks. The micro-cracks in the vertical direction became the main cracks, which mainly expanded with the conjoining of contiguous voids at the crack tip front. Micro-cracks in other directions grew along the grain boundaries and led to material shedding.
