By defining the yield stress in a latent hardening test as the first deviation from the elastic straight line, the yielding and hardening behavior on a latent system in the positive and negative slip direction was stu...By defining the yield stress in a latent hardening test as the first deviation from the elastic straight line, the yielding and hardening behavior on a latent system in the positive and negative slip direction was studied in aluminium single crystals. It is shown that the yield stresses on both the positive and negative latent systems are about equal to or a little lower than the maximum resolved shear stress in the primary test, but much higher than that of the active system. The Influence of relative orientation and prestrain on latent hardening and initial work-hardening in the secondary test was also investigated, and it was found that there is a considerable effect on initial work-hardening, but none on latent hardening. With reasonable approximation, a hardening rule for single crystal could be proposed from the experimental results, that is, except for the yield stress on the system negative to the active system that is very low, hardening on the other systems is nearly the same as self-hardening.展开更多
A modified Miedema model and pattern recognition technique are used to establish the criteria for the formation of continuous solid solutions in alloy systems, and to study the occurrence of the melting temperature mi...A modified Miedema model and pattern recognition technique are used to establish the criteria for the formation of continuous solid solutions in alloy systems, and to study the occurrence of the melting temperature minimum of continuous solid solutions.展开更多
A hyper-ellipsoid model, using genetic algorithm as method of computation, has been proposed to be used in certain metallurgical processes. It is especially suitable for the modelling of the metallurgical processes wi...A hyper-ellipsoid model, using genetic algorithm as method of computation, has been proposed to be used in certain metallurgical processes. It is especially suitable for the modelling of the metallurgical processes with data-structure of 'inclusion type'.展开更多
The multi-dimensional spaces, spanned by the dimensionless numbers describing the equilibrium states or the macroscopic chemical kinetics of complicated chemical reaction systems, have been used for the data processin...The multi-dimensional spaces, spanned by the dimensionless numbers describing the equilibrium states or the macroscopic chemical kinetics of complicated chemical reaction systems, have been used for the data processing of the process-es in materials preparation or industrial production. It has been found that there are four common topological types of the rela-tions between the optimization zone and the operation zone in the multi-dimensional spaces. Various computation methods us-ing pattern recognition, artificial neural network and genetic algorithm are used for model-building and optimization strategy searching. An integrated system named KDPAG has been built for materials optimal design or industrial optimization. Appli-cation to chemical, petrochemical and metallurgical industries and materials optimal design gives good results.展开更多
The submicron powder mixtures of TiC-TiN-WC-Mo-C-Ni sintered at 1400degreesC or below in vacuum were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) an...The submicron powder mixtures of TiC-TiN-WC-Mo-C-Ni sintered at 1400degreesC or below in vacuum were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The results showed that Mo2C formed at 800degreesC or below. Both WC and Mo2C disappeared at 1200degreesC, and TiN disappeared at 1250degreesC. In addition, the variations of lattice constants of the titanium carbonitride and nickel binder phase with sintering temperature were experimentally obtained, and the reason was analyzed.展开更多
文摘By defining the yield stress in a latent hardening test as the first deviation from the elastic straight line, the yielding and hardening behavior on a latent system in the positive and negative slip direction was studied in aluminium single crystals. It is shown that the yield stresses on both the positive and negative latent systems are about equal to or a little lower than the maximum resolved shear stress in the primary test, but much higher than that of the active system. The Influence of relative orientation and prestrain on latent hardening and initial work-hardening in the secondary test was also investigated, and it was found that there is a considerable effect on initial work-hardening, but none on latent hardening. With reasonable approximation, a hardening rule for single crystal could be proposed from the experimental results, that is, except for the yield stress on the system negative to the active system that is very low, hardening on the other systems is nearly the same as self-hardening.
文摘A modified Miedema model and pattern recognition technique are used to establish the criteria for the formation of continuous solid solutions in alloy systems, and to study the occurrence of the melting temperature minimum of continuous solid solutions.
文摘A hyper-ellipsoid model, using genetic algorithm as method of computation, has been proposed to be used in certain metallurgical processes. It is especially suitable for the modelling of the metallurgical processes with data-structure of 'inclusion type'.
文摘The multi-dimensional spaces, spanned by the dimensionless numbers describing the equilibrium states or the macroscopic chemical kinetics of complicated chemical reaction systems, have been used for the data processing of the process-es in materials preparation or industrial production. It has been found that there are four common topological types of the rela-tions between the optimization zone and the operation zone in the multi-dimensional spaces. Various computation methods us-ing pattern recognition, artificial neural network and genetic algorithm are used for model-building and optimization strategy searching. An integrated system named KDPAG has been built for materials optimal design or industrial optimization. Appli-cation to chemical, petrochemical and metallurgical industries and materials optimal design gives good results.
基金This work wasfinancially supported by the National Natural Science Foundation Of China (50074017), the NationalDoctorate Progr
文摘The submicron powder mixtures of TiC-TiN-WC-Mo-C-Ni sintered at 1400degreesC or below in vacuum were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The results showed that Mo2C formed at 800degreesC or below. Both WC and Mo2C disappeared at 1200degreesC, and TiN disappeared at 1250degreesC. In addition, the variations of lattice constants of the titanium carbonitride and nickel binder phase with sintering temperature were experimentally obtained, and the reason was analyzed.
