• Development of an efficient e-waste recycling and beneficiation method into separable precious metals 

  Nkhoma, Richard; Ngonda, Tiyamike; Mwale, Vincent Dodoma; Falayi, Thabo; Siyasiya, Charles Witness (EDP Sciences, 2024-03)

  Please read abstract in the article.
• Gas formation of cobalt and copper in the application of unconstrained Co-Cr-Al-Cu metal powders in submerged arc welding : gas phase thermodynamics and 3D slag SEM evidence 

  Coetsee, Theresa; De Bruin, Frederik (MDPI, 2023-04-05)

  Aluminium metal is not typically added to the submerged arc welding (SAW) process because it is easily oxidised to form unwanted slag in the weld pool. The successful application of aluminium as a de-oxidiser is illustrated ...
• EERZ (effective equilibrium reaction zone) model of gas-slag-metal reactions in the application of unconstrained Al-Ni-Cr-Co-Cu metal powders in submerged arc welding : model and 3D slag SEM evidence 

  Coetsee, Theresa; De Bruin, Frederik (MDPI, 2023-07-14)

  The scope of this work is to improve the SAW process understanding and present an improved description of the SAW process in terms of gas-slag-metal reactions with alloy powder and Al powder additions. The scope does not ...
• Chemical behaviour of copper in the application of unconstrained Cr-Ni-Al-Cu metal powders in submerged arc welding : gas phase thermodynamics and 3D slag SEM evidence 

  Coetsee, Theresa; De Bruin, Frederik (MDPI, 2023-02)

  Unconstrained metal powders of Cu, Cr, Ni and Al were applied to submerged arc welding (SAW) to clarify the chemical behaviour of copper in this modified SAW process. Aluminium metal is avoided in SAWbecause it is easily ...
• A review of the thermochemical behaviour of fluxes in submerged arc welding : modelling of gas phase reactions 

  Coetsee, Theresa; De Bruin, Frederik (MDPI, 2023-03)

  This review is focused on the thermochemical behaviour of fluxes in submerged arc welding (SAW). The English-language literature from the 1970s onwards is reviewed. It was recognised early on that the thermochemical ...
• Utilization of silicon dust to prepare Si3N4 used for steelmaking additives : thermodynamics and kinetics 

  Hu, Qian; Xue, Zhengliang; Song, Shengqiang; Cromarty, Robert Douglas; Chen, Yiliang (MDPI, 2024-02)

  Please read abstract in the article.
• Nano-strand formation via gas phase reactions from Al-Co-Fe reacted with CaF2-SiO2-Al2O3-MgO flux at 1350 °C : SEM study and thermochemistry calculations 

  Coetsee, Theresa; De Bruin, Frederik (MDPI, 2024-07)

  Please read abstract in the article.
• Strain-induced martensitic transformation and the mechanism of wear and rolling contact fatigue of AISI 301LN metastable austenitic stainless steel 

  Leso, Tshenolo Phinah; Mukarati, Tulani W.; Mostert, R.J. (Roelf); Siyasiya, Charles Witness (Wiley, 2024-09)

  AISI 301LN metastable austenitic stainless steels (MASSs) are known to exhibit high work-hardening rates attributed to martensite evolution during straining which results in the second-phase strengthening mechanism. This ...
• Investigation of network microstructure of TiB/Ti6Al4V-ELI composite manufactured with laser metal deposition 

  Lekoadi, Paul; Tlotleng, Monnamme; Siyasiya, Charles Witness; Masina, Bathusile N. (Springer, 2023-08)

  This work presents the microstructural investigation of an in situ synthesized TiB/Ti6Al4V-ELI composite that was manufactured with additive manufacturing (AM) technique known as laser metal deposition (LMD). A single-track ...
• Limits on Ti element transfer in submerged arc welding : thermochemical analysis 

  Coetsee, Theresa; De Bruin, Frederik (Wiley, 2024-05)

  Please read abstract in the article.
• Hand-held XRF sorting of spent refractory bricks to aid recycling 

  Mabasa, N.P.; Naude, N.; Garbers-Craig, Andrie Mariana (Southern African Institute of Mining and Metallurgy, 2023-01)

  An improved methodology is presented for assessing the economic feasibility and effectiveness of recycling MgO-C and Al2O3-MgO-C refractory bricks, which are widely used in the steelmaking industry. Since approximately ...
• Electrical resistivity of heat-treated charcoal 

  Cromarty, Robert Douglas; Bharat, S.; Odendaal, D. (Southern African Institute of Mining and Metallurgy, 2023-10)

  The aim of this investigation was to determine the effect of high-temperature heat treatment on the electrical resistivity of charcoal. Samples of two different wood types (eucalyptus and black wattle) were pyrolised in ...
• Material characteristics of Ti-6AL-4V samples additively manufactured using laser-based direct energy deposition 

  Willemse, Mattian G.; Siyasiya, Charles Witness; Marais, D.; Venter, A.M.; Arthur, N.K.K. (Southern African Institute of Mining and Metallurgy, 2023-02)

  Although additive manufacturing is fast gaining traction in the industrial world as a reputable manufacturing technique to complement traditional mechanical machining, it still has problems such as porosity and residual ...
• Copper solvent extraction on the African Copperbelt : from historic origins to world-leading status 

  Tinkler, O.S.; Sole, Kathryn C. (Southern African Institute of Mining and Metallurgy, 2023-07)

  Approximately 20% of current world copper cathode output is produced using a hydrometallurgical process route, generally referred to as the leach–solvent extraction–electrowinning flowsheet. Since its commercialization ...
• Low temperature vaporisation of Cr from fluoride flux reacted at 1350 ° C with Al -Cr -Fe powder : thermochemical analysis of gas phase reactions and nano-strand formation 

  Coetsee, Theresa; De Bruin, Frederik (Elsevier, 2024-05)

  The submerged arc welding (SAW) process is complex because multi-phase reactions occur simultaneously across a large temperature interval from 2500 °C in the arc cavity, down to the weld pool liquidus temperare at the ...
• The role of hydrogen in the corrosion-induced reduction of plane-stress fracture toughness and strain-induced intergranular cracking of AA2024 

  Pretorius, Christiaan C.E.; Mostert, Roelf Johannes; Charalampidou, C.-M.; Alexopoulos, N. (Elsevier, 2024)

  The role of diffusible hydrogen in the embrittlement of AA2024 after short-term exposure in the standard exfoliation corrosion (EXCO) test solution (ASTM G34) was investigated. Slow strain rate KR-curves were established ...
• Criteria for the onset of structural integrity degradation due to high- temperature hydrogen attack of a carbon-manganese steel 

  Mostert, Roelf Johannes; Van Zyl, A.; Pretorius, Christiaan C.E.; Mathoho, Vhutshilo M. (Elsevier, 2024)

  Please read abstract in the article.
• The effect of soaking time on mechanical properties of roll-bonded AA3003 and AA4045 used for heat exchangers 

  Moema, Joseph; Siyasiya, Charles Witness; Morudu, Veronica K.; Buthelezi, Thokozani (MDPI, 2023-09)

  Due to the rising need for energy saving, high-performing automotive heat exchangers, demand has significantly grown in recent years. As a result, effective fin-tube heat exchangers are becoming more popular. These tubes ...
• Low-cycle fatigue behaviour of titanium-aluminium-based intermetallic alloys : a short review 

  Ellard, John J.M.; Mathabathe, Maria N.; Siyasiya, Charles Witness; Bolokang, Amogelang S. (MDPI, 2023-08)

  Over the past decade, relentless efforts have brought lightweight high-temperature γ-TiAl-based intermetallic alloys into real commercialisation. The materials have found their place in General Electric’s (GE) high bypass ...
• Effects of lubrication on wear and rolling contact fatigue behavior of class B wheel steels against R350HT rail steels using a twin-disc wear simulator 

  Leso, Tshenolo Phinah; Siyasiya, Charles Witness; Mostert, Roelf Johannes; Moema, Joseph (Taylor and Francis, 2023)

  Wear and rolling contact fatigue (RCF) are major causes of delays and unavailability of rail systems. The presence of lubricants at the rail and wheel interface influences wear and RCF. Lubricants include naturally occurring ...

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