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Abstract: Based on the logarithmic strain’s principle of
superposition and volume compressible material’s plastic function, the
analytic formulas for large forging porosity and cavity ratio, stress
and deformation are established . Then the porosity collapse factor is
given. Through the discussion of the relationship between porous
material’s cavity ratio and stress, deformation, it can be concluded
that stress state and strain state play an irreplaceable role in
porosity collapse process. The existence of hydrostatic stress is the
prerequisite of porosity collapse process. At the beginning of the
collapse process, hydrostatic stress plays an important role, and at the
end of the collapse process, deformation takes the function of reducing
stress value. An experiment is also carried out using lead porous
material. The result shows the porosity collapse factor given can be
well used in real production for reference.
Key words: Material processing Plastic mechanics Plastic
deformation Large forging
CLC No: TG316
教育部博士点基金资助项目(97021606). Received 20010926, received in revised form
20020204
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