Mechanical Properties of Ti-15Mo Alloy Prepared by Cryogenic Milling and Spark Plasma Sintering

Abstract

Metastable β-Ti alloy Ti-15Mo was prepared by cryogenic ball milling in a slurry of liquid argon. Material remained ductile even at low temperatures, which suppressed particle refinement, but promoted intensive plastic deformation of individual powder particles. Repetitive deformation of powder particles is similar to the multidirectional rolling and resembles bulk severe plastic deformation (SPD) methods. Initial and milled powders were compacted by spark plasma sintering. Sintered milled powder exhibited a refined microstructure with small β-grains and submicrometer sized α-phase precipitates. The microhardness and the yield tensile strength of the milled powder after sintering at 850 °C attained 350 HV and 1200 MPa, respectively. Low ductility of the material can be attributed to high oxygen content originating from the cryogenic milling. This pioneering work shows that cryogenic milling followed by spark plasma sintering is able to produce two-phase β-Ti alloys with refined microstructure and very high strength levels.

Study on Corrosion Behavior of Ultrafine-Grained Ti-6Al-7Nb Fabricated by Equal Channel Angular Pressing

“…Ti-6Al-7Nb alloy, a modified type of Ti-6Al-4V by replacing the toxic V by bio-inert Nb and maintaining the good mechanical properties, is considered as a better material for biomedical application [9,10]. Recently, ultrafine-grained (UFG) and nanocrystalline (NC) materials processed by severe plastic deformation (SPD) have been widely investigated and found to have unique physical and chemical properties [11][12][13]. Enhanced mechanical behavior and biocompatibility of UFG/NC Ti-6Al-7Nb alloy were acquired after the SPD process [14][15][16][17][18][19].…”

Severe Plastic Deformation and Thermomechanical Processing: Nanostructuring and Properties

“…Thirteen research papers have been published in this Special Issue of Metals. The papers cover a wide spectrum of topics, including (i) deformation mechanisms, the mechanical properties and fatigue behaviour of SPD-processed materials [1][2][3][4][5][6][7], (ii) microstructural and mechanical stability at elevated temperatures [8,9], phase formations in alloys [10], the improvement of physical properties (electrical conductivity [11], magneto-resistance [12]) and biomedical properties (biocorrosion resistance [6], biocompatibility [13]) by SPD.…”

“…Furthermore, intermetallic precipitates contributed to the strength. Veverková et al [7] evaluated the mechanical properties of a metastable β-Ti alloy Ti-15Mo, which was prepared by cryogenic milling and spark plasma sintering. By using this process, a refined microstructure with very high strength levels could be obtained.…”

Investigation of mechanical properties and microstructure of Ti-15% Mo alloy produced by mechanical alloying and sintering with SPS (MA-SPS)

“…Therefore, it can melt the surfaces of Ti powder particles and its alloys while applying pressure and high-pulsed DC current and cause bonding between powder particles and their compression [24]. Veverková et al fabricated a Ti-Mo alloy using SPS under high pressures [25][26][27]. This method is based on maintaining the grain size of the material sintered and is also designed to minimize porosity and achieve high density [22].…”