35 results about "Crystal plasticity" patented technology

The invention provides a method for predicting coupling responses of isothermal forming and dynamic recrystallization evolution of titanium alloys. Grain stress responses, intercrystalline non-uniform deformation and non-uniform dislocation density caused by intercrystalline non-uniform deformation are obtained in an isothermal forming process of the titanium alloys and are adopted as variables and transmitted to a cellular automaton, dynamic recrystallization evolution of the grain size under the condition of non-uniform size deformation is obtained, and dynamic recrystallization nucleation and grown structure morphology as well as grain boundary evolution and updated dislocation density which are caused by the dynamic recrystallization nucleation and grown structure morphology are obtained. The obtained grain and grain boundary information including dynamic recrystallization nucleation and growth as well as the dislocation density is returned to a crystal plasticity finite element method, dislocation gliding resistance of each grain unit is updated, so that subsequent deformation of the titanium alloys is influenced, and the stress responses of the grain size are calculated according to the constitutive relation. The method realizes synchronous prediction of non-uniform deformation of the grain size in isothermal forming of the titanium alloys, dynamic recrystallization structure morphology evolution, recrystallized grain size evaluation, recrystallization kinetics, deformable bodies and grain flow stress.

The invention discloses a three-dimensional crystal plastic finite element modeling method and system for crystal material parts. The data of real crystal material parts is obtained, and the distribution law is obtained according to the obtained data; the distribution law of the obtained crystal grain size data is the minimum value of the crystal material part model. The oriented bounding box generates grain size data; generates the grain scale model of the smallest oriented bounding box; removes redundancy from the grain scale model, and obtains the three-dimensional pseudo-random grain scale microstructure of crystal material parts; through the obtained grain orientation data Distribution law and grain boundary misorientation data distribution law, iteratively assign orientation to each grain in the three-dimensional pseudo-random grain-scale microstructure; through the obtained three-dimensional pseudo-random grain-scale microstructure of crystal material parts and the grain size Orientation data, construct crystal plastic finite element model of crystal material parts; realize crystal plastic finite element simulation. The invention can be used for mechanical performance simulation and service simulation.

The invention discloses a fast calculation method for the constitutive behavior of multi-phase metal materials facing high-speed deformation process. The mechanical behavior of each single pure phase in the multi-phase material is predicted by the crystal plasticity finite element method, and then the mechanical behavior of each single pure phase in the multi-phase material is predicted by the metallographic structure measurement, The proportional mixing method predicts the macroscopic constitutive behavior exhibited by the material in the multiphase state. This method can accurately and rapidly predict the mechanical behavior of a single phase of the material under high strain rate state, so it can be applied to high-speed machining, forging and other deformation processes involving steel, titanium alloy and other materials with complex phase composition. This method avoids the need to re-measure the mechanical behavior of the material due to the significant change in the mechanical properties after different heat treatments for the same material. In practical industrial production, it can significantly reduce costs and improve simulation and analysis efficiency. Computer-aided analysis and design of part machining deformation process is of great significance.

The invention relates to a method for predicting the strength of a defect-containing structure high-entropy alloy. Effectively combine dislocation theory, crystal plasticity theory, and defect theory to establish relevant strength theoretical models. The influence of dislocations, dislocation loops and severe lattice distortion effects on the properties of high-entropy alloys is considered to achieve quantitative calculation of the strength of high-entropy alloys with defect structures. The yield strength obtained by the prediction method proposed in the present invention is in good agreement with the experimental results. The relevant deformation mechanism analyzed in the present invention is of great significance for studying and predicting the influence of dislocation loop defects on the strength of high-entropy alloys. Through the prediction method proposed in the present invention, the element content of the alloy is regulated, and the influence of different element content on the yield strength is studied, thereby providing theoretical guidance for the design of high-performance high-entropy alloys. In the development process of new alloys, the method effectively avoids a large number of repeated tests, shortens the research and development cycle of high-performance high-entropy alloys, saves costs, and has great engineering value.

A method for improving the plasticity of amorphous alloys at room temperature, which belongs to the field of material technology research, specifically relates to a method for improving and enhancing the plasticity of amorphous alloys by coating the surface with a layer of metallic nickel for the characteristics of high strength but very low plasticity of amorphous alloys. method of crystal plasticity. It is characterized in that the plasticity of the formed bulk metallic glass structure is improved by means of electroplating. The basic process is as follows: the first step is to use a high-vacuum non-consumable arc melting furnace to produce the required real amorphous test pattern ; The second step is to carry out pre-plating treatment on the pattern; the third step is to coat the surface of the amorphous sample with a layer of crystalline metal by electroplating. The plasticity of the amorphous composite material produced by the invention is obviously improved, and the amorphous structure still maintains the original glass state.

The invention discloses a semi-quantitative prediction and visualization method of mesoscopic stress and texture in the deformation process of alpha titanium, and belongs to the technical field of material plastic deformation. The invention solves the problem that the existing simulation means or experimental method is difficult to obtain the mesoscopic stress, and avoids the high requirements and high cost of equipment for the experimental characterization of the mesoscopic stress. In this application, the representative volume element RVE is used as a carrier to establish a crystal plasticity model, and the texture obtained by EBSD characterization or XRD measurement is imported into the representative volume element RVE. The representative volume element RVE is composed of titanium alloy α phase and contains the texture information of the original experimental material. The subsequent crystal plasticity simulation takes into account the slip and twinning deformation behavior of α titanium alloy, and can obtain and visualize the mesoscopic stress and texture evolution information of the material under various external loads. The evolution of microscopic stress and the initiation and propagation of mesoscopic stress-induced cracks are crucial.

The invention belongs to the field of precise and efficient processing of a micro part, and particularly relates to a cutting process simulation-based single-crystal copper micro-milling force forecast method. The cutting process simulation-based single-crystal copper micro-milling force forecast method comprises the steps of initially and comprehensively considering influence of factors such as crystal deformation kinematics, a crystal plasticity constitutive relation and hardening law of rate-dependent crystal on single-crystal copper micro-milling due to the specialty of a single-crystal copper material; secondly, deducing an incremental form of a constitutive equation, writing single-crystal copper VUMAT user material sub-program by employing a Fortran language, and introducing crystalplasticity constitution into a finite element simulation; and finally, performing simulation modeling on the single-crystal copper micro-milling process by ABAQUS software to achieve single-crystal copper micro-milling force forecast. By taking finite cutting simulation as a basis, accurate forecast of a single-crystal copper micro-milling force is achieved, a technical support is provided for researching the single-crystal copper micro-milling process, the processing accuracy and efficiency of single-crystal copper micro-milling is improved, and the cutting process simulation-based single-crystal copper micro-milling force forecast method has a practical application value.