Spark Plasma Sintering of Mechanically Milled Pure Titanium with Stearic Acid Additive

Abstract

Pure titanium powder was mechanically milled (MMed) using a vibrational ball mill with stearic acid. The MMed powders were consolidated by spark plasma sintering (SPS). Two sintering conditions were selected in order to understand the effect of the spark plasma sintering time on mechanical properties of bulk pure titanium. The mechanical properties and microstructures of SPS materials sintered at 1073 K for 180 s with the heating rate of 1.67 K/s and at 1073 K for 1.8 ks with the heating rate of 1 K/s were compared. The SPS materials produced by two different sintering conditions exhibited almost the same hardness and similar microstructure. Near-full density was achieved for the SPS materials for 180 s under an applied pressure of 49 MPa at a temperature of 1073 K. Formation of TiC by solid-state reaction was observed for the SPS materials consolidated from 4 and 8 h MMed powders. A maximum Vickers hardness of 933 HV obtained for the SPSed material fabricated from 4 h MMed powder with 0.50 g of PCA.