A comparative study of spark plasma sintering and hybrid spark plasma sintering of W-4.9ni-2.1Fe heavy alloy
- Authors: Shongwe, Mxolisi Brendon , Diouf, Saliou , Durowoju, Mondiu Olayinka , Olubambi, Peter Apata , Ramakokovhu, Munyadziwa Mercy , Obadele, Babatunde Abiodun
- Date: 2016
- Subjects: Tungsten heavy alloys , Spark plasma sintering , Microstructure
- Type: Article
- Identifier: http://hdl.handle.net/10210/123454 , uj:20793 , Citation: Shongwe, M.B. et al. 2016. A comparative study of spark plasma sintering and hybrid spark plasma sintering of W-4.9ni-2.1Fe heavy alloy.
- Description: Abstract: Mixed 93W-4.9Ni-2.1Fe powders were sintered via the spark plasma sintering (SPS) and hybrid spark plasma sintering (HSPS) techniques with 30 mm and 60 mm samples in both conditions. After SPS and HSPS, the 30 mm and 60 mm alloys (except 60mm-SPS) had a relative density (>99.2%) close to the theoretical density. Phase, microstructure and mechanical properties evolution of W-Ni-Fe alloy during SPS and HSPS were studied. The microstructural evolution of the 60 mm alloys varied from the edge of the sample to the core of the sample. Results show that the grain size and the hardness vary considerable from the edge to the core of sintered sample of 60 mm sintered using conventional SPS compared to hybrid SPS. Similarly, the hardness also increased from the edge to the core. The 60 mm-HSPS alloy exhibit improved bending strength than the 60 mm-SPS, 1115 MPa and 920 MPa respectively, former being similar to the 30 mm-SPS and HSPS alloys. The intergranular fracture along the W/W grain boundary is the main fracture modes of W-Ni-Fe, however in the 60 mm-SPS alloy peeling of the grains was also observed which diminished the properties. The mechanical properties of SPS and HSPS 93W-4.9Ni-2.1Fe heavy alloys are dependent on the microstructural parameters such as tungsten grain size and overall homogeneity.
- Full Text:
Processing of pure titanium containing titanium-based reinforcing ceramics additives using spark plasma sintering
- Authors: Diouf, Saliou , Durowoju, Mondiu Olayinka , Shongwe, Mxolisi Brendon , Olubambi, Peter Apata
- Date: 2017
- Subjects: Spark plasma sintering , Titanium matrix composites , Ceramics
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/240416 , uj:24730 , Citation: Diouf, S. 2017. Processing of pure titanium containing titanium-based reinforcing ceramics additives using spark plasma sintering. Leonardo Electronic Journal of Practices and Technologies. 269-286. , ISSN: 1583-1078
- Description: Abstract: The densification behaviour, microstructural changes and hardness characteristics during spark plasma sintering of CP-Ti reinforced with TiC, TiN, TiCN and TiB2 were investigated. Commercially pure Ti powders were dry mixed with varied amounts (2.5 and 5 wt. %) of the ceramic additives using a T2F Turbula mixer for 5 h and at a speed of 49 rpm. The blended composite powders were then sintered using spark plasma sintering system (model HHPD-25 from FCT Germany) at a heating rate of 100oC min-1, dwell time of 5 min and sintering temperature of 950ºC. The sintering of CP-Ti was used as a base study to select the proper spark plasma sintering temperature for full density. Densification was monitored through analysis of the recorded punch displacement and the measured density of the sintered samples using Archimedes method. High densities ranging from 97.8% for 5% TiB2 addition to 99.6% for 5% TiCN addition were achieved at a relatively low temperature of 950°C...
- Full Text: