FeAl/TiC composites were fabricated by reactive hot pressing blended elemental powders. The TiC content was varied from 50% to 80%(volume fraction) and the aluminum content in the binder phase was changed from 40% to ...FeAl/TiC composites were fabricated by reactive hot pressing blended elemental powders. The TiC content was varied from 50% to 80%(volume fraction) and the aluminum content in the binder phase was changed from 40% to 50%(mole fraction). The effects of these compositional changes on the densification process and mechanical properties were studied. The results show that with the increase of TiC content, densities of the composites decrease due to insufficient particle rearrangement aided by (dissolutionreprecipitation) reaction during hot pressing. Closely related with their porosities and defect amount, the hardness and bend strength of the composites show peak values, attaining the highest values with TiC content being 70% and 60%, respectively. Increasing the aluminum content is beneficial to the densification process. But the hardness and bend strength of the composites are reduced to some extent due to the formation of excessive oxides and thermal vacancies.展开更多
To explore the problems of dynamic change in production demand and operating contradiction in production process, a new extension theory-based production operation method is proposed. The core is the demand requisitio...To explore the problems of dynamic change in production demand and operating contradiction in production process, a new extension theory-based production operation method is proposed. The core is the demand requisition, contradiction resolution and operation classification. For the demand requisition, the deep and comprehensive demand elements are collected by the conjugating analysis. For the contradiction resolution, the conflict between the demand and operating elements are solved by the extension reasoning, extension transformation and consistency judgment. For the operating classification, the operating importance among the operating elements is calculated by the extension clustering so as to guide the production operation and ensure the production safety. Through the actual application in the cascade reaction process of high-density polyethylene (HDPE) of a chemical plant, cases study and comparison show that the proposed extension theory-based production operation method is significantly better than the traditional experience-based operation method in actual production process, which exploits a new way to the research on the production operating methods for industrial process.展开更多
文摘FeAl/TiC composites were fabricated by reactive hot pressing blended elemental powders. The TiC content was varied from 50% to 80%(volume fraction) and the aluminum content in the binder phase was changed from 40% to 50%(mole fraction). The effects of these compositional changes on the densification process and mechanical properties were studied. The results show that with the increase of TiC content, densities of the composites decrease due to insufficient particle rearrangement aided by (dissolutionreprecipitation) reaction during hot pressing. Closely related with their porosities and defect amount, the hardness and bend strength of the composites show peak values, attaining the highest values with TiC content being 70% and 60%, respectively. Increasing the aluminum content is beneficial to the densification process. But the hardness and bend strength of the composites are reduced to some extent due to the formation of excessive oxides and thermal vacancies.
基金Supported by the National Natural Science Foundation of China(61104131)the Fundamental Research Funds for Central Universities(ZY1111)
文摘To explore the problems of dynamic change in production demand and operating contradiction in production process, a new extension theory-based production operation method is proposed. The core is the demand requisition, contradiction resolution and operation classification. For the demand requisition, the deep and comprehensive demand elements are collected by the conjugating analysis. For the contradiction resolution, the conflict between the demand and operating elements are solved by the extension reasoning, extension transformation and consistency judgment. For the operating classification, the operating importance among the operating elements is calculated by the extension clustering so as to guide the production operation and ensure the production safety. Through the actual application in the cascade reaction process of high-density polyethylene (HDPE) of a chemical plant, cases study and comparison show that the proposed extension theory-based production operation method is significantly better than the traditional experience-based operation method in actual production process, which exploits a new way to the research on the production operating methods for industrial process.
