Powder metallurgy and mechanical alloying effects on the formation of thermally induced martensite in an FeMnSiCrNi SMA

Pricop B., Mihalache E., Lohan M., Istrate B., Mocanu M., Özkal B., ...Daha Fazla

10th European Symposium on Martensitic Transformations (ESOMAT), Antwerp, Belçika, 14 - 18 Eylül 2015, cilt.33 identifier identifier

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Cilt numarası: 33
  • Doi Numarası: 10.1051/matecconf/20153304004
  • Basıldığı Şehir: Antwerp
  • Basıldığı Ülke: Belçika
  • İstanbul Teknik Üniversitesi Adresli: Evet

Özet

By ingot metallurgy (IM, melting, alloying and casting), powder metallurgy (PM, using as-blended elemental powders) and mechanical alloying (MA of 50 % of particle volume), three types of FeMnSiCrNi shape memory alloy (SMA) specimens were fabricated, respectively. After specimen thickness reduction by hot rolling, solution treatments were applied, at 973 and 1273 K, to thermally induce martensite. The resulting specimens were analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), in order to reveal the presence of epsilon (hexagonal close-packed, hcp) and alpha' (body centred cubic, bcc) thermally induced martensites. The reversion of thermally induced martensites, to gamma (face centred cubic, fcc) austenite, during heating, was confirmed by dynamic mechanical analysis (DMA), which emphasized marked increases of storage modulus and obvious internal friction maxima on DMA thermograms. The results proved that the increase of porosity degree, after PM processing, increased internal friction, while MA enhanced crystallinity degree.