Abstract
Micropores are decisive to mechanical properties and thermal deformation capabilities of powder met-allurgy(P/M)Ti alloys sintered compacts.As a result,achieving express densification is of prime im-portance and has attracted increasing attention recently.Induction heating owns the merits of high effi-ciency,short process,and low cost,and thus has huge potential to be used as a sintering approach for the fabrication of P/M Ti alloys.Nevertheless,the facilitated densification behavior associated with induction heating sintering remains unclear so far.To address it,powder metallurgy Ti6Al4V is manufactured via induction heating sintering with which the underlying sintering mechanism is investigated in-depth.It is found that induction heating could generate a fully densified compact in a remarkably shortened time,demonstrating its superior sintering efficiency as compared with conventional resistance furnace heat-ing.COMSOL finite element analysis reveals that the maximum current density during induction heating can reach 106 A m-2 though the magnetic field strength is solely 0.02 T,leading to a slight tempera-ture difference of approximately 30 ℃ between the interior and exterior of the billet.Furthermore,the rapid heating essentially starts at sharp corners of particles due to the potent current concentration ef-fect,which facilitates the cracking of the particle surface oxide film and thus enhances the direct contact between them.Moreover,the electromigration effect caused by induction current promotes the diffusion capability of elements,giving rise to expedited densification,alloying,and chemical homogenization.This work provides not only critical insight into the sintering mechanism of induction heating sintering but also significant guidance for low-cost powder metallurgy materials preparation.
基金项目
国家重点研发计划(2020YFB2008300)
国家自然科学基金(51971097)
国家自然科学基金(52301147)
Young Elite Scientists Sponsorship Program by China Association for Science and Technology(YESS20210054)
湖北省自然科学基金(ZRMS2022000863)
Fundamental Research Funds for the Central Universities of Huazhong University of Science and Technology(2172021XXJS010)
State Key Laboratory of Powder Metallurgy,Central South University,Changsha,China()
NETL
NSTL
万方数据