TY - JOUR
T1 - Effects of in-situ formed TiB whiskers on microstructure and mechanical properties of spark plasma sintered Ti-B4C and Ti-TiB2 composites
AU - Sabahi Namini, A.
AU - Azadbeh, M.
AU - Shahedi Asl, M.
N1 - Publisher Copyright:
© 2018 Sharif University of Technology. All rights reserved.
PY - 2018/3/1
Y1 - 2018/3/1
N2 - Monolithic titanium, Ti-1 wt% B4C, and Ti-2.5 wt% TiB2 were spark plasma sintered at 1050°C for 5 min under 50 MPa. The effects of B4C and TiB2 additions on densification process, microstructural development, and mechanical properties of titanium were investigated. The results revealed that relative density of undoped as well as B4Cand TiB2-doped Ti samples reached ∼98-99%. X-ray diffraction patterns, thermodynamic assessments, and microstructural investigations verified the in-situ formation of TiB whiskers in both composite samples as well as the appearance of TiC spheres in Ti-B4C composite. However, trace unreacted TiB2 and B4C additives remained in the composites as a result of incomplete chemical reactions due to short-time SPS process. Compared to undoped Ti sample, grain growth was hindered when the sample was doped by B4C or TiB2. Elongation, ultimate tensile strength, and Vickers hardness of B4C-or TiB2-doped samples were higher than those of monolithic titanium, but bending strength of ceramicdoped samples was significantly lower, compared to undoped titanium. These outcomes were discussed in detail and related to the presence/formation of several ceramic phases with different morphologies in Ti matrix.
AB - Monolithic titanium, Ti-1 wt% B4C, and Ti-2.5 wt% TiB2 were spark plasma sintered at 1050°C for 5 min under 50 MPa. The effects of B4C and TiB2 additions on densification process, microstructural development, and mechanical properties of titanium were investigated. The results revealed that relative density of undoped as well as B4Cand TiB2-doped Ti samples reached ∼98-99%. X-ray diffraction patterns, thermodynamic assessments, and microstructural investigations verified the in-situ formation of TiB whiskers in both composite samples as well as the appearance of TiC spheres in Ti-B4C composite. However, trace unreacted TiB2 and B4C additives remained in the composites as a result of incomplete chemical reactions due to short-time SPS process. Compared to undoped Ti sample, grain growth was hindered when the sample was doped by B4C or TiB2. Elongation, ultimate tensile strength, and Vickers hardness of B4C-or TiB2-doped samples were higher than those of monolithic titanium, but bending strength of ceramicdoped samples was significantly lower, compared to undoped titanium. These outcomes were discussed in detail and related to the presence/formation of several ceramic phases with different morphologies in Ti matrix.
KW - Ceramic additives
KW - Mechanical properties
KW - Microstructure
KW - Spark plasma sintering
KW - TiB whisker
KW - Titanium
UR - http://www.scopus.com/inward/record.url?scp=85031940216&partnerID=8YFLogxK
U2 - 10.24200/sci.2017.4499
DO - 10.24200/sci.2017.4499
M3 - Article
AN - SCOPUS:85031940216
SN - 1026-3098
VL - 25
SP - 762
EP - 771
JO - Scientia Iranica
JF - Scientia Iranica
IS - 2B
ER -