Three experimental single crystal superalloys with 0%Nb,0.5%Nb,1.0%Nb were cast in the directionally solidified furnace,while other alloying element contents were basically kept unchanged.The effect of Nb on the micro...Three experimental single crystal superalloys with 0%Nb,0.5%Nb,1.0%Nb were cast in the directionally solidified furnace,while other alloying element contents were basically kept unchanged.The effect of Nb on the microstructure,stability at1100°C and stress rupture properties at 1070°C and 160 MPa of the single crystal superalloy were investigated.The experiment results show that the primary dendrite arm spacing decreases and the volume fraction ofγ/γ′eutectic of the alloy increases with the increase of Nb content in the as-cast microstructures.The size ofγ′phase particles becomes small and uniform and the cubic shape does not obviously change with the increase of Nb content.The precipitating rate and volume fraction of TCP phases increase significantly with the increase of Nb content in the process of long term aging at 1100°C.The stress rupture lives increase and elongation decreases with increasing Nb content at 1070°C/160 MPa.At last,the relationship between the microstructures stability,stress rupture properties of the alloy and Nb content is discussed based on JMat Pro software and the lastest relevant database for single crystal superalloy.展开更多
According to energy partition principle,we have derived a generalized formula used to calculate the radiation effi-ciency.It overcomes the numerical errors involved in the estimation of radiation efficiency caused by ...According to energy partition principle,we have derived a generalized formula used to calculate the radiation effi-ciency.It overcomes the numerical errors involved in the estimation of radiation efficiency caused by the uncer-tainties owe to the different frictional mechanisms which is used to describe the earthquake faulting.Using real seismic data published in the previous studies,we have recalculated the radiation efficiency with associated to the different frictional mechanisms,and compared with previous results lack of consideration of frictional mechanism.The results indicate that,based on the new formula,the radiation efficiency we have estimated is always less than 1,and the unphysical conclusion of radiation efficiency greater than 1 is avoided completely.展开更多
Based on the discrete wavenumber method, we calculate the fields of dynamic Coulomb rupture stress changes and static stress changes caused by M6.5 earthquake in Wuding, and study their relationship with the subsequen...Based on the discrete wavenumber method, we calculate the fields of dynamic Coulomb rupture stress changes and static stress changes caused by M6.5 earthquake in Wuding, and study their relationship with the subsequent after- shocks. The results show that the spatial distribution patterns of the positive region of dynamic stress peak value and static stress peak value are similarly asymmetric, which are basically identical with distribution features of aftershock. The dynamic stress peak value and the static stress in the positive region are more than 0.1 MPa and 0.01 MPa of the triggering threshold, respectively, which indicates that the dynamic and static stresses are helpful for the occurrence of aftershock. This suggests that both influences of dynamic and static stresses should be con- sidered other than only either of them when studying aftershock triggering in near field.展开更多
采用电弧离子镀技术在IC10合金基体上制备N iCrA lYS i粘结层,采用电子束物理气相沉积(EB-PVD)技术在粘结层上制备YSZ陶瓷面层,研究TBCs涂层对IC10合金高温持久性能的影响。结果表明,IC10合金沉积TBCs涂层后,980℃高温持久寿命高于IC10...采用电弧离子镀技术在IC10合金基体上制备N iCrA lYS i粘结层,采用电子束物理气相沉积(EB-PVD)技术在粘结层上制备YSZ陶瓷面层,研究TBCs涂层对IC10合金高温持久性能的影响。结果表明,IC10合金沉积TBCs涂层后,980℃高温持久寿命高于IC10合金,持久塑性略高于基体合金,IC10合金沉积TBCs涂层后,对高温持久性能无不良影响,满足使用要求。展开更多
文摘Three experimental single crystal superalloys with 0%Nb,0.5%Nb,1.0%Nb were cast in the directionally solidified furnace,while other alloying element contents were basically kept unchanged.The effect of Nb on the microstructure,stability at1100°C and stress rupture properties at 1070°C and 160 MPa of the single crystal superalloy were investigated.The experiment results show that the primary dendrite arm spacing decreases and the volume fraction ofγ/γ′eutectic of the alloy increases with the increase of Nb content in the as-cast microstructures.The size ofγ′phase particles becomes small and uniform and the cubic shape does not obviously change with the increase of Nb content.The precipitating rate and volume fraction of TCP phases increase significantly with the increase of Nb content in the process of long term aging at 1100°C.The stress rupture lives increase and elongation decreases with increasing Nb content at 1070°C/160 MPa.At last,the relationship between the microstructures stability,stress rupture properties of the alloy and Nb content is discussed based on JMat Pro software and the lastest relevant database for single crystal superalloy.
基金National Natural Science Foundation of China (40574022)Special Research Project of Welfare Institute (ZDJ2007-1)One Hundred Talent Project of Chinese Academy of Sciences.
文摘According to energy partition principle,we have derived a generalized formula used to calculate the radiation effi-ciency.It overcomes the numerical errors involved in the estimation of radiation efficiency caused by the uncer-tainties owe to the different frictional mechanisms which is used to describe the earthquake faulting.Using real seismic data published in the previous studies,we have recalculated the radiation efficiency with associated to the different frictional mechanisms,and compared with previous results lack of consideration of frictional mechanism.The results indicate that,based on the new formula,the radiation efficiency we have estimated is always less than 1,and the unphysical conclusion of radiation efficiency greater than 1 is avoided completely.
文摘Based on the discrete wavenumber method, we calculate the fields of dynamic Coulomb rupture stress changes and static stress changes caused by M6.5 earthquake in Wuding, and study their relationship with the subsequent after- shocks. The results show that the spatial distribution patterns of the positive region of dynamic stress peak value and static stress peak value are similarly asymmetric, which are basically identical with distribution features of aftershock. The dynamic stress peak value and the static stress in the positive region are more than 0.1 MPa and 0.01 MPa of the triggering threshold, respectively, which indicates that the dynamic and static stresses are helpful for the occurrence of aftershock. This suggests that both influences of dynamic and static stresses should be con- sidered other than only either of them when studying aftershock triggering in near field.
文摘采用电弧离子镀技术在IC10合金基体上制备N iCrA lYS i粘结层,采用电子束物理气相沉积(EB-PVD)技术在粘结层上制备YSZ陶瓷面层,研究TBCs涂层对IC10合金高温持久性能的影响。结果表明,IC10合金沉积TBCs涂层后,980℃高温持久寿命高于IC10合金,持久塑性略高于基体合金,IC10合金沉积TBCs涂层后,对高温持久性能无不良影响,满足使用要求。
