Effect of heat treatment and number of passes on the microstructure and mechanical properties of friction stir processed AZ91C magnesium alloy

Dadashpour M., YEŞİLDAL R., MOSTAFAPOUR A., REZAZADE V.

JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY, cilt.30, sa.2, ss.667-672, 2016 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 30 Sayı: 2
  • Basım Tarihi: 2016
  • Doi Numarası: 10.1007/s12206-016-0121-x
  • Dergi Adı: JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.667-672
  • Anahtar Kelimeler: AZ91C magnesium alloy, Heat treated, Microstructural characterization, Mechanical properties, PROCESS PARAMETERS
  • Atatürk Üniversitesi Adresli: Evet

Özet

In this paper, the effect of heat treatment and number of passes on microstructure and mechanical properties of friction stir processed AZ91C magnesium alloy samples were investigated. From six samples of as-cast AZ91C magnesium alloy, three plates were pre-heated at temperature of 375 degrees C for 3 hours, and then were treated at temperature of 415 degrees C for 18 hours and finally were cooled down in air. Three plates were relinquished without heat treatment. 8 mm thick as-cast AZ91C magnesium alloy plates were friction stir processed at constant traverse speed of 40 mm/min and tool rotation speed of 1250 rpm. After process, microstructural characterization of samples was analyzed using optical microscopy and tensile and Vickers hardness tests were performed. It was found that heat treated samples had finer grains, higher hardness, improved tensile strength and elongation relative to non-heat treated ones. As the number of passes increased, higher UTS and TE were achieved due to finer grains and more dissolution of beta phase (Mg17Al12). The micro-hardness characteristics and tensile improvement of the friction stir processed samples depend significantly on grain size, removal of voids and porosities and dissolution of beta phase in the stir zone.