Ni,Cr,Al-TaC自生复合材料的定向凝固组织特性

本文采用高梯度定向凝固装置制备Ni TaC共晶自生复合材料。系统地研究了凝固速率对凝固组织的影响。随凝固速率增大 ,固液界面依次呈现平一胞一枝的形貌。TaC纤维增强相的平均间距和截面积随凝固速率增大而减小 ,其体积分数可在一定范围内调节。与此同时 ,随凝固速率的增大 ,γ′相形貌趋于规整 ,尺寸减小。

HIGH-TEMPERATURE TENSILE FRACTURE BEHAVIOR OF DIRECTIONALLY SOLIDIFIED Ni,Cr,Al-TaC EUTECTIC SUPERALLOY

The high-temperature tensile fracture behavior of the Ni, Cr, Al-TaC eutectic superal-loy directionally solidified under high temperature gradient is investigated. The high-temperature tensile fracture of this in situ composite has ductile character with lots of ductile nests whose diameters decrease with the increasing solidification rates. The maximum σb and δ are respectively 668.5MPa and 19.6%. There is α TaC whisker in the center of each nest, and the deformation of γ' and TaC is uneven. The high-temperature tensile behavior cannot be explained by the rule of mixtures but is decided by the formation of the plastic deformation band. The crack extension model is given.

隔壁塔(DWC)在NMP精制过程中的应用

传统的N-甲基吡咯烷酮(NMP)精制要需常压塔、负压脱水塔和精馏塔三塔串联操作,过程复杂且能耗较高。本文首先对某企业的NMP精制过程进行了数据采集、模拟计算及优化,并以优化的传统工艺年总成本(TAC)为基准,与侧线采出和隔壁塔工艺(DWC)进行对比。结果显示:当前运行工艺优化后可节能30%以上。DWC比优化传统工艺操作操作费用高4.56%,但投资费用低约15.15%,TAC比传统工艺降低近2.4%,具有显著的优越性。