Achieving uniform microstructure and superior mechanical properties in ultrafine grained TiB2–TiSi2 composites using innovative multi stage spark plasma sintering

The spark plasma sintering (SPS) technique was employed to prepare compacts from (i) gas-atomized and (ii) attritor-milled AE42 magnesium powder. Short attritor-milling was used mainly to disrupt the MgO shell covering the powder particles and, in turn, to enhance consolidation during sintering. Compacts prepared by SPS from the milled powder featured finer microstructures than compacts consolidated from gas-atomized powder (i.e., without milling), regardless of the sintering temperatures in the range of 400–550 °C. Furthermore, the grain growth associated with the increase in the sintering temperature in these samples was less pronounced than in the samples prepared from gas-atomized particles. Consequently, the mechanical properties were significantly enhanced in the material made of milled powder. Apart from grain refinement, the improvements in mechanical performance were attributed to the synergic effect of the irregular shape of the milled particles and better consolidation due to effectively disrupted MgO shells, thus suppressing the crack formation and propagation during loading. These results suggest that relatively short milling of magnesium alloy powder can be effectively used to achieve superior mechanical properties during consolidation by SPS even at relatively low temperatures.

Download Full-text

Ultrafine-grained Ti66Nb13Cu8Ni6.8Al6.2 composites fabricated by spark plasma sintering and crystallization of amorphous phase

Journal of Materials Research ◽

10.1557/jmr.2009.0231 ◽

2009 ◽

Vol 24 (6) ◽

pp. 2118-2122 ◽

Cited By ~ 33

Author(s):

Y.Y. Li ◽

C. Yang ◽

W.P. Chen ◽

X.Q. Li ◽

S.G. Qu

Keyword(s):

Mechanical Properties ◽

Powder Metallurgy ◽

Spark Plasma Sintering ◽

Amorphous Phase ◽

Fracture Strength ◽

High Fracture ◽

Plasma Sintering ◽

Ultrafine Grained ◽

Spark Plasma

We report on the formation of ultrafine-grained Ti66Nb13Cu8Ni6.8Al6.2 composites with in situ precipitated micrometer-sized β-Ti(Nb) phase by spark plasma sintering with crystallization. Microstructure analysis indicated that all alloys consisted of soft (Cu, Ni)Ti2 regions surrounded by hard β-Ti(Nb) regions but displayed different microstructures. The alloys exhibited high fracture strength of more than 2200 MPa and remarkable plasticity of ∼25%. The results provided a promising method for fabricating large-sized bulk composites with excellent mechanical properties by powder metallurgy.

Download Full-text

Fabrication of ultrafine grained FeCrAl-0.6 wt.% ZrC alloys with enhanced mechanical properties by spark plasma sintering

Advanced Powder Technology ◽

10.1016/j.apt.2021.02.041 ◽

2021 ◽

Author(s):

Haiyi Wan ◽

Xuguang An ◽

Qingquan Kong ◽

Xiaoqiang Wu ◽

Wei Feng ◽

...

Keyword(s):

Mechanical Properties ◽

Spark Plasma Sintering ◽

Plasma Sintering ◽

Ultrafine Grained ◽

Spark Plasma

Download Full-text

Two-Step Spark Plasma Sintering Process of Ultrafine Grained WC-12Co-0.2VC Cemented Carbide

Materials ◽

10.3390/ma12152443 ◽

2019 ◽

Vol 12 (15) ◽

pp. 2443 ◽

Cited By ~ 1

Author(s):

Zhenhua Wang ◽

Jiheng Jia ◽

Boxiang Wang ◽

Yulin Wang

Keyword(s):

Mechanical Properties ◽

Relative Density ◽

Spark Plasma Sintering ◽

Average Particle Size ◽

Cemented Carbide ◽

Cemented Carbides ◽

Average Particle ◽

Plasma Sintering ◽

Ultrafine Grained ◽

Spark Plasma

Ultrafine grained WC-12Co-0.2VC (named UYG12V) cemented carbides were prepared via the two-step spark plasma sintering (SPS) in this study. First, the effects of the sintering temperature on the relative density and WC grain size of UYG12V cemented carbides were studied. The results show that regular WC grains form when sintered at 1300 °C. The sintered body begins to rapidly densify and WC grains grow slowly when sintered at 1200 °C. Thus, the first-step (T1) and the second-step (T2) temperatures in the two-step SPS of UYG12V are 1300 °C and 1200 °C, respectively. The effect of the holding time during the first and second steps on the mechanical properties was also studied. The results show that the UYG12V cemented carbide sintered at 1300 °C for 3 min and then at 1200 °C for 5 min has the best comprehensive mechanical properties, exhibiting the average particle size, Vickers hardness, fracture toughness, relative density, and bending strength of 271 nm, 18.06 GPa, 12.25 MPa m1/2, 99.49%, and 1960 MPa, respectively.

Download Full-text