• Decomposition of sulfide phases and subsequent matte collection in the black top of a platinum group metal smelter 

  Rivera Li Kao, Oscar; Garbers-Craig, Andrie Mariana (Taylor and Francis, 2025)

  This study explored, on a laboratory scale, how matte separates from the gangue in the black top of a PGM smelter. Two PGM concentrates, one with high sulfide content (17.3 mass%, Platreef concentrate) and the other with ...
• The role of niobium during heat treatment of high-vanadium high-speed steel rolls for improved mechanical properties 

  Chauke, Rivoningo E.; Siyasiya, Charles Witness; Nyabadza, Davisn (Springer, 2024-12)

  High-speed steel (HSS) provides superior wear resistance and high surface quality of rolled-steel products. In this study, the influence of niobium addition on the solidification behavior and microstructure of high-speed ...
• First-principle study on tailoring the martensitic transformation of B2 Nb50−xTixRu50 shape-memory alloy for structural applications 

  Nkomo, Duduzile; Shen, Yu-Nien; Mostert, R.J. (Roelf); Yamabe-Mitarai, Yoko; Phasha, Maje (MDPI, 2024-09)

  NbRu has a potential as a high-temperature shape-memory alloy (HTSMA) because it has a martensitic transformation temperature above 1000 ◦C. However, its shape-memory properties could be improved for consideration in the ...
• Effect of coiling temperature on microstructures and precipitates in high-strength low-alloy pipeline steel after heavy reduction during a six-pass rolling thermo-mechanical controlled process 

  Lei, Yicong; Yang, Wen; Siyasiya, Charles Witness; Tang, Zhenghua (MDPI, 2024-02-18)

  Nb-Ti high-strength low-alloy pipeline steel was subjected to a six-pass rolling process followed by the coiling process at different temperatures between 600 and 650 ◦C using the thermomechanical testing system Gleeble ...
• Correlation between elastic properties and phase transformation of Zr50Pd50-xRux high-temperature shape memory alloys designed by DFT 

  Shen, Yu-Nien; Nkomo, Duduzile; Matsunaga, S.; Phasha, M.J.; Yamabe-Mitarai, Y. (Springer, 2024-09)

  The effect of Ru addition on the martensitic transformation and mechanical properties of Zr50Pd50 xRux SMAs shape memory alloys has been studied. Strain–temperature experiments, differential scanning calorimeter, and ...
• Incompressible versus compressible fluid flow models : a case study on furnace tap-hole lancing 

  Erwee, Markus Wouter; Reynolds, Q.G.; Zietsman, Johannes Hendrik (Southern African Institute of Mining and Metallurgy, 2024-03)

  Pyrometallurgical furnaces, essential for metal extraction, operate at temperatures exceeding 1600°C and represent complex multiphase systems that challenge direct industrial research. Multiphysics models play a key role ...
• Extraction of rare earth elements from Phalaborwa phosphogypsum 

  Wildenboer, R.A.; Sandenbergh, Roelf (Southern African Institute of Mining and Metallurgy, 2024-10)

  Rare earth elements (REE) are present at concentrations of approximately 0.36 % in phosphogypsum stacks located in Phalaborwa, South Africa. The REE are present in the phosphogypsum in solid solution in the gypsum and ...
• Investigating optimum hot working window of 2205 duplex stainless steel using modified dynamic material modeling 

  Gonya, Elvis M.; Makhatha, Mamookho E.; Siyasiya, Charles Witness; Silubane, Ndumiso M.; Kibambe, Ngeleshi M. (Springer, 2025)

  Please read abstract in the article.
• Timed thermodynamic process model applied to submerged arc welding modified by aluminium-assisted metal powder alloying 

  Coetsee, Theresa; De Bruin, Frederik (Springer, 2024-11)

  An EERZ (effective equilibrium reaction zone) model was applied to the modified SAW (submerged arc welding) process to simulate the SAW process metallurgy in the gas-slag-metal reaction system. The SAW process was modified ...
• Mechanical and thermal properties of calcined clay mixed with agrowaste char for sustainable building applications 

  Agyei-Tufour, Benjamin; Sewordor, Michael E.; Bafoe, John F.; Forson, Martha; Ampah-Essel, John Ekow; Ardayfo, Beatrice; Kadiri-English, Bashiru; Marfo, Kwame K.; Adjah, John; Asante, Joshua Tuah; Nyankson, Emmanuel; Dodoo-Arhin, David (Wiley, 2024)

  Please read abstract in the article.
• 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.

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