把TiBCN陶瓷粉末和Mn粉末混合(其中TiCB含量分别是100 wt%、95 wt%、90wt%、80 wt%和60 wt%)作为熔覆材料,用5 k W CO_2激光对Ti6-Al4-V(TC4)合金进行激光熔覆处理。用扫描电子显微镜(SEM)、能谱仪(EDS)和X-射线衍射仪(XRD)分析熔覆层中...把TiBCN陶瓷粉末和Mn粉末混合(其中TiCB含量分别是100 wt%、95 wt%、90wt%、80 wt%和60 wt%)作为熔覆材料,用5 k W CO_2激光对Ti6-Al4-V(TC4)合金进行激光熔覆处理。用扫描电子显微镜(SEM)、能谱仪(EDS)和X-射线衍射仪(XRD)分析熔覆层中TiBCN颗粒的形貌和反应产物。观察发现,激光熔覆层没有形成裂纹,TiBCN颗粒发生部分熔化,并和金属发生反应生成TiN_(0.2)、Al_3Ti、TiAl和MnB等新相。TiBCN颗粒之间连接紧密,自动组装成枝晶状组织,与基体呈冶金结合状态。TiBCN颗粒和基体发生传质,基体中的Al元素扩散到TiBCN,形成多元Ti(Al)BCN固溶体。测试表明,熔覆层硬度明显提高达到HV1300,耐磨性比基体提高了4倍。展开更多
A novel drop unit for the optical code-division multiple access(OCDMA) based on fiber Bragg gratings and two-dimensional wavelength-time code is studied.The simple OCDMA drop unit can drop a code channel without distu...A novel drop unit for the optical code-division multiple access(OCDMA) based on fiber Bragg gratings and two-dimensional wavelength-time code is studied.The simple OCDMA drop unit can drop a code channel without disturbing the rest code channels.A similar unit for dropping a group of code channels is also proposed.Numerical simulation is given.The system delay can decrease by substituting the electrieal driving optical switch with a specific optical driving.The single channel drop unit can also be the basis for multiple channels drop.展开更多
文摘把TiBCN陶瓷粉末和Mn粉末混合(其中TiCB含量分别是100 wt%、95 wt%、90wt%、80 wt%和60 wt%)作为熔覆材料,用5 k W CO_2激光对Ti6-Al4-V(TC4)合金进行激光熔覆处理。用扫描电子显微镜(SEM)、能谱仪(EDS)和X-射线衍射仪(XRD)分析熔覆层中TiBCN颗粒的形貌和反应产物。观察发现,激光熔覆层没有形成裂纹,TiBCN颗粒发生部分熔化,并和金属发生反应生成TiN_(0.2)、Al_3Ti、TiAl和MnB等新相。TiBCN颗粒之间连接紧密,自动组装成枝晶状组织,与基体呈冶金结合状态。TiBCN颗粒和基体发生传质,基体中的Al元素扩散到TiBCN,形成多元Ti(Al)BCN固溶体。测试表明,熔覆层硬度明显提高达到HV1300,耐磨性比基体提高了4倍。
基金Supported by National Hi-tech863 project(No.2002 AA 311141)
文摘A novel drop unit for the optical code-division multiple access(OCDMA) based on fiber Bragg gratings and two-dimensional wavelength-time code is studied.The simple OCDMA drop unit can drop a code channel without disturbing the rest code channels.A similar unit for dropping a group of code channels is also proposed.Numerical simulation is given.The system delay can decrease by substituting the electrieal driving optical switch with a specific optical driving.The single channel drop unit can also be the basis for multiple channels drop.
