Study On Compressive Deformation Behavior Of Pure Mo Powder Sintered

Molybdenum is a kind of high points and melting points of refractory metals, because of their special properties, which used more and more extensive range of applications in recent years. So molybdenum and molybdenum alloy is be a hot topic as scholars study. Molybdenum and molybdenum alloy produce primary by the method of powder metallurgy, but the above method has some limitations, such as high production costs, long cycle. The research based on the molybdenum powder processing technology is the preparation for producing high capability of molybdenum and molybdenum alloy billets and has a certain significance of refractory metals.This paper analyzes the plastic deformation of powder materials, theories, methods based on the theory of compressible rigid plastic, consider the volume average stress and strain the relationship between the applied powder derived constitutive equations of compressible material and by the compression of data to determine the coefficients of constitutive equation, expand and enrich powder plastic theory. Through the suppression of pure molybdenum powder test, analysis of molybdenum powder material in the production blank of the compact law; by the sintering, obtain the densification law of powder sintering process for the molybdenum billet. By deformation under different sintering molybdenum powder obtain deformation behavior. From the process of compression experiment, study the relationship of strain, strain rate, temperature, relative density and mechanical properties of relations. Basis on the study of experiment, use Deform-3D to model and simulate. From experimental results we obtained in a good agreement. Verified through experiment and simulation, provide experimental basis for further studies on molybdenum powder materialThrough suppression and Sintering of, at the conclusion on the basis of the law of the system blank, we successfully obtain the relative density of molybdenum powder of 0.7-0.98 sintered sample. From the compression experiments, we obtained flow stress increased with the increase of the relative density, as the strain rate increases, decreases with increasing temperature, but the strain rate on flow stress is weak. By metallographic analysis and micro-hardness testing of grain deformation during compression deformation, the mechanism reduced by the changes of porosity and hardness obtained with the strain increases and the relative density also increased. In addition, the higher the relative density of the sample, the compression prone to brittle fracture, and deformation is difficult to carry out further processing, but showed better under high temperature deformation capacity.