Showing 3 results for Spark Plasma Sintering
Z. Sadeghian, R. Dezfulizadeh,
Volume 13, Issue 2 (6-2016)
Abstract
In situ Al2024- Mg2Si composite was fabricated by spark plasma sintering (SPS) of reactive powder. Reactive powder was obtained from mechanical alloying (MA) of elemental powders. Clad layers of in situ composite were fabricated on Al substrates by spark plasma sintering (SPS). Structural evolution during MA process and after SPS was investigated by X-ray diffractometery (XRD). Scanning electron microscopy (SEM) was utilized to study the microstructure of sintered samples. Hardness and tensile behavior of sintered samples were investigated. The results showed that SPS of mechanically alloyed unreacted powder can result in the in situ formation of Mg2Si and Mg2Al3 within the Al matrix. SPSed clad layer showed a sound and clear interface to the Al substrate with a hardness of about 140 HV. Sintered in situ composite exhibited a tensile strength of 288 MPa.
Sasan Ranjbar Motlagh, Hosein Momeni, Naser Ehsani,
Volume 18, Issue 1 (3-2021)
Abstract
In this study, the effect of annealing treatment on microstructure and mechanical properties of Nb-10Hf-1Ti wt.% produced by Spark Plasma Sintering (SPS) was investigated. Scanning electron microscope (SEM), optical microscopy, X-ray diffraction analysis, hardness, and uniaxial tension test were used. Annealing treatment was carried out in a vacuum of 10-3 Pa at 1150 °C for 1, 3, 5, and 7 hours and in an argon atmosphere at 1350 °C for 5 hours. Internal oxidation and subsequent hafnium oxide formation causes the hardening of the C103 alloy and drastically increases hardness and tensile strength. Although HfO2 particles formed in the grain boundary cause brittleness and cleavage fracture of samples. Volume fraction, particle size, and mean interparticle spacing of oxides significantly change by annealing and subsequently the mechanical properties are affected. The SPSed sample at 1500 ℃ is softened by annealing at 1150 ℃ for 5 hours and its hardness and yield strength are reduced from 303 Hv to 230 Hv and 538 MPa to 490 MPa respectively. While annealing at 1350 ℃for 5 hours increases hardness and yield strength increases to 343 Hv and 581 MPa.
Mohammad Jafaripour, Hassan Koohestani, Behrooz Ghasemi,
Volume 18, Issue 4 (12-2021)
Abstract
In this study, aluminum matrix composites reinforced with Al2O3 and SiC nanoparticles, and graphene nanoplatelets produced by Spark Plasma Sintering (SPS) were studied. The microstructural and mechanical properties of the composites were evaluated by changing the amounts of the reinforcing materials. The SEM images showed that the reinforcing particles were more distributed in the grain boundary regions. According to the results, the addition of alumina and SiC to the matrix caused an increase in the composite density whereas the composite density decreased by adding graphene nanoplatelets. The highest relative density of 96.3% was obtained for the composite containing 2 wt% Al2O3. The presence of the reinforcing particles increased the hardness of all the samples compared to the pure aluminum (39 HV). The composite containing 1 wt.% Al2O3, 0.7 wt.% SiC, and 0.3 wt.% graphene showed the highest hardness of 79 HV. Moreover, the plastic deformation of the specimens decreased and the slope of the plastic region increased by adding the reinforcing particles to the matrix.
