Improvement of Ti Processing through Colloidal Techniques Articles uri icon

authors

  • GARCIA DAS NEVES, ROBERTO
  • ESCRIBANO, J.A.
  • Ferrari, Begoña
  • GORDO ODERIZ, ELENA
  • SANCHEZ HERENCIA, ANTONIO JAVIER

publication date

  • August 2012

start page

  • 335

end page

  • 340

volume

  • 520

International Standard Serial Number (ISSN)

  • 1013-9826

Electronic International Standard Serial Number (EISSN)

  • 1662-9809

abstract

  • The colloid-chemistry control of metallic powders in aqueous slurries is proposed as a way to prepare Ti powders with small particle size for a better pressing behavior through the spray dry process. The chemical-physic behavior of titanium powders with two different particle size distributions dispersed in water has been studied by measuring the zeta potential as a function of pH, and dispersant concentration. The employment of poly-acrylic dispersants allowed the fabrication of stable slurries with solid contents up to 50 vol% that have been sprayed under different conditions to form agglomerates ranging between 50 and 200 µm. Conditions were selected to achieve spherical agglomerates formed by a broad distribution of particle sizes that shown excellent flowability. Agglomerates were pressed in a uniaxial die to measure the compressibility, showing an improvement in pressing behavior with respect to powders with bigger particle size. The sintering behavior is also improved, as values of 96 % of the theoretical density were obtained for compacts sintered in vacuum at 1100 ºC for 30 minutes.