'n Ondersoek na die eienskappe en skakelgedrag van silikonkarbiedvlakveldeffektransistors vir hoedrywingstoepassings.
- Authors: Wolmarans, Johan Jacob
- Date: 2008-07-25T06:21:05Z
- Subjects: Field-effect transistors , Semiconductor switches , Silicon carbide's electric properties , Silicon carbide
- Type: Thesis
- Identifier: uj:7418 , http://hdl.handle.net/10210/826
- Description: The current temperature operating range of semiconducting materials is given to be between -10°C and 105°C. Current plans are to increase this range due to an industry demand for semiconducting materials able to operate outside these bounds. Wide bandgap semiconductor materials have been researched for some time in an effort to manufacture commercially viable controlled semiconductor switches. Samples of such a controlled switch have been obtained and promises to be close to commercial rollout. This controlled switch takes on the form of a Junction Field Effect Transistor (JFET), which is a depletion mode component. Depletion mode switches are normally-on, and have thus far not been used in the power electronics field. Due to difficult switching and availibility of component which are switched more easily, these components were quicklier and easierly adopted for use. The Silicon Carbide JFET promises to circumvent these cons with the ability to block higher voltages, at higher temperatures and at higher speeds. Lower on resistance and smaller size of substrates are other benefits that the use of Silicon Carbide semiconducting material promises. A variety of properties of the Silicon Carbide JFET are investigated. Some of these properties include the component on-resistance, gate charge, breakthrough voltage of the gate and leakage current of the channel. Switching performance is also investigated as well as the reverse recovery of the body diode. All properties were measured as a function of temperature in an effort to describe the difference in performance at high temperatures. , Prof. Ivan Hofsajer
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Evaluation of microstructural and nanomechanical performance of spark plasma sintered TiFe-SiC reinforced aluminium matrix composites
- Authors: Akinwamide, Samuel Olukayode , Lesufi, Miltia , Akinribide, Ojo Jeremiah , Mpolo, Peggy , Olubam, Peter Apata
- Date: 2020
- Subjects: Spark plasma sintering , Aluminium , Silicon carbide
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/444284 , uj:38831 , Citation: Akinwamide, S.O. et al. 2020. Evaluation of microstructural and nanomechanical performance of spark plasma sintered TiFe-SiC reinforced aluminium matrix composites.
- Description: Abstract: tDue to the increasing demand for lighter materials with enhanced properties, the upgrade oftechniques to improve the production of high-performance composite materials is of greatinterest in modern technology. The microstructural and mechanical properties of sparkplasma sintered aluminium based composites with ferrotitanium (TiFe) and silicon carbide(SiC) reinforcements were investigated. High energy ball milling technique was adopted toeffectively disperse the particles SiC and TiFe reinforcements into the matrix of aluminium,and the admixed powders were compacted using spark plasma sintering technique. Thespecimens sectioned from the sintered compacts were analysed using an X-ray diffractome-ter (XRD), optical microscope (OM), and field emission scanning electron microscope (FESEM)to understand the microstructural features and phase evolution of the sintered compos-ites. The mechanical properties of the composites were also investigated through hardness,nanomechanical and tribology tests. Results from the microstructural examinations con-ducted shows that the reinforcement particles were evenly dispersed within the aluminiummatrix, as a result of the milling process. Furthermore, all the sintered composites hadtheir microstructural features enhanced, but properties such as hardness, frictional coeffi-cient, and elastic modulus were more enhanced in specimen reinforced with 2%SiC+2%TiFeparticles. The reduced crystallite size recorded by the sintered specimens confirmed theeffectiveness of the milling process, and powder metallurgy route adopted for fabrication.
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