Prediction of flow stress at hot working condition

In this review, the formability characteristics of Aluminium based composites using FEM and statistical tool are discussed. Formability characteristics of Metal Matrix Composites (MMCs) have been influenced by many factors viz., temperature, pressure, volume fraction of reinforcement, size and shape of particles. Investigation on wall friction, friction between particles and matrix powder are also presented. Detailed review has been carried out on the workability studies on upsetting of MMCs and forming limit diagrams. The state of the art has been discussed with the help of literatures.

Formability Characteristics of Aluminium Based Composites-A Review

A study of flow characteristics of nanostructured Al-6082 alloy produced by ECAP under upsetting test

The evolution of eutectic carbide in as-cast M2 high speed steel was investigated with hot compression test and metallographic examination. Initial rodlike or irregular eutectic carbides were broken into smaller particles during hot deformation by thermomechanical disintegration, while diffusion-controlled phase transformation was not remarkable. Combining with numerical simulation, the relationship between breakdown ratio of carbide network and deformation parameters was obtained. Strain was the most important driving force to shatter eutectic carbides and disperse products. Furthermore, critical strain values were obtained, beyond which carbide network disappeared, and fractured carbides kept a stable profile and they were deformed with matrix coordinately. A higher temperature or lower strain rate resulted in a lower critical strain.

Breakdown Behavior of Eutectic Carbide in High Speed Steel During Hot Compression

This manuscript presents a combined numerical and experimental methodology for determining the stress-strain curve of metallic materials from the measurements of force and displacement obtained in the axial compression of cylindrical test specimens with friction between the specimens and the platens The methodology is based on minimizing the error between the average surface pressure obtained from the experimental measurements of the force and displacement and that obtained from the slab method of analysis of metal plasticity Three different friction models based on Coulomb friction, the constant friction model or combined friction models are utilized Experimental results obtained from cylindrical and Rastegaev test specimens with different lubricants combined with the experimental determination of friction by means of ring compression tests allows compensating the effect of friction in the determination of the material flow curve Comparison with the flow curves determined without friction compensation shows the viability of the proposed methodology The proposed methodology is a simple and effective alternative to other solutions available in the literature and the pseudo-code supplied in the Appendix is provided for those readers interested in utilizing the associated numerical algorithm for determining the stress-strain curves of metallic materials

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Friction Compensation in the Upsetting of Cylindrical Test Specimens

Determination of metal material flow stress by the method of C-FEM

Research on the flow stress characteristics of AISI 1006 and AISI 5140 in the temperature range of warm forging by means of thermo-mechanical experiments

Flow stress of carbon steel 08F in temperature range of warm-forging

During forging parts' process design, there usually exist several process routes which can be chosen. In order to get the best process route, first, mathematical models for process evaluation and optimization are set up respectively. Then finite element simulation technology is adopted to simulate all process sequences. The aim is to get those process parameters that the former mathematical models needed, such as stress, strain, and load. Through the combination of those two techniques, the best process route can be acquired quickly. What's more, the cost for moulds' trials can be cut down sharply also.

Lin Xinbo

Papers

Determination of metal material flow stress by the method of C-FEM

Research on the flow stress characteristics of AISI 1006 and AISI 5140 in the temperature range of warm forging by means of thermo-mechanical experiments

Flow stress of carbon steel 08F in temperature range of warm-forging

Process evaluation and optimization based on numerical simulation