Open AccessComprehensive finite-element study of processes for the production of titanium strips by asymmetric cold rolling of a powder followed by sintering
Author(s) -
I. Yu. Prykhodko,
Maxim Dedik,
Stefan Brandt,
K. A. Gogaev,
A. I. Itsenko,
V. S. Voropaev
Publication year - 2019
Publication title -
fundamentalʹnye i prikladnye problemy černoj metallurgii/fundamental and applied problems of ferrous metallurgy
Language(s) - English
Resource type - Journals
eISSN - 2786-6149
pISSN - 2522-9117
DOI - 10.52150/2522-9117-2019-33-173-192
Subject(s) - sintering , materials science , compaction , relative density , finite element method , von mises yield criterion , titanium powder , strips , titanium , composite material , metallurgy , structural engineering , engineering
Finite-element numerical modeling was implemented and a study of the production processes of thin titanium strips was carried out on the basis of two key sequential processes: asymmetric powder rolling and sintering of the rolled product using the Brand-Nielson model. The results of studying the processes of compaction and sintering of titanium powder using a single mathematical model proposed by Jan Brandt are presented. For the calculations we used experimentally determined shear stresses and volumetric compression modulus under hydrostatic compression and uniaxial compression. The friction conditions between the surfaces of the rolls and the powder were determined as a function of the change in the Coulomb coefficient of friction on the relative sliding speed of the surfaces of the roll and the workpiece. An analysis of the results allows a quantitative assessment of the influence of the technology parameters of the compaction and sintering processes on the change in the stress state and relative density in the volume of products at the stages of production processes. It is shown that the application of the von Mises density and stress diagrams for the correction of the sintering regime allows avoiding the appearance of defects (insufficiently uniform density of the sintered material and the presence of microcracks) during intense heating of the metal in the furnace. The development of sintering modes based on the Brand-Nielson model simplifies the improvement of technology in the sintering of bulk bodies, which is a more time-consuming process than sintering of thin plates. This model can be used in the development of sintering regimes for various materials since it takes into account the influence of basic phenomena in this process. By varying the technology parameters it is possible to achieve targeted effects on product quality indicators and prevent the formation of microcracks in them.