Rio Tinto Aluminium (previously known as Comalco) is now known as Rio Tinto Alcan after Rio's takeover of Alcan. It was the world's eighth largest aluminium company. It mines and manufactures bauxite, alumina and primary aluminium.Rio Tinto Aluminium is a wholly owned subsidiary of Rio Tinto Group and provides about 20% of Australia's total production of bauxite, 8% of its alumina and 24% of its primary aluminium.In 2002, Rio Tinto Aluminium earned US$256 million for its shareholder Rio Tinto.In 2006 Rio Tinto Aluminium was the largest receiver of budgetary assistance from the Australian government, Rio Tinto Aluminium had received over $287 million in assistance from Australian tax dollars.RTA owns the Weipa Bauxite mine, Yarwun Alumina Refinery, and Bell Bay aluminium smelter.
This study investigates microstructural and mechanical property variations in a full-scale AA5083 direct-chill cast slab ingot. Chemical segregation, grain size gradients, intermetallic compound morphology, and porosity distribution were characterized across top, middle, and bottom sections. Magnesium fluctuations, Fe-rich intermetallic size, and porosity density were found to strongly influence hardness, tensile strength, and elongation, particularly in the quarter-thickness region. Results show that solidification conditions and local cooling rates drive microstructural heterogeneity, explaining measured property deviations of 10–15 support improved quality control and future specification development for as-cast AA5083 plates.
The use of aluminumAluminum extrusionExtrusion alloys in the automotiveAutomotive sector is increasing in response to the need for a reduction in the mass of battery electric and internal combustion engine vehicles. The microstructureMicrostructure of the material can be tailored by careful control of extrusionExtrusion conditions. In the current study, the microstructureMicrostructure was varied by modifying the billet temperature and the extrusionExtrusion ram speed. The mechanical propertiesMechanical properties were examined by conducting uniaxial tensile tests for naturally aged (T4) and artificially aged (T5/T6) tempers. It was observed that the yield and ultimate tensile stresses were lower in the material with a smaller grain size but the ductility as measured by the true strain to fracture was similar for the T4 temper materials regardless of grain size, while in the T5/T6 tempers the material with the larger grain size had a lower true strain to fracture compared to the smaller grain size material.
Trace additions of Sn (0.05 and 0.15 wt.%) and Sr (0.006 and 0.013 wt.%) combined with a novel two-step aging treatment were introduced into Al-Zr-Sc conductor alloys to investigate their effects on microstructure and mechanical properties. The additions of Sn or Sr, together with two-step aging, improved the mechanical strength and electrical conductivity (EC) of the alloys. In the Sn15 alloy, two-step aging enhanced microhardness, ultimate tensile strength, and EC to 78.3 HV, 216 MPa, and 58.3% IACS (International Annealed Copper Standard), respectively, compared with 74.2 HV, 206 MPa, and 57.5% IACS after conventional one-step aging. Similarly, the Sr13 alloy exhibited improved properties, with 83.2 HV, 227 MPa, and 58.0% IACS after two-step aging, versus 78.3 HV, 215 MPa, and 57.5% IACS with one-step aging. These improvements-5.5 HV, 10 MPa, and 0.8% IACS for the Sn15 alloy; 5.2 HV, 12 MPa, and 0.7% IACS for the Sr13 alloy-are primarily attributed to the precipitation of a larger number of fine Al3(Sc, Zr) strengthening precipitates. Early-stage Al3(Sc, Zr) precipitation was observed in the Sn15 alloy after the first-step aging at 300 degrees C for 4 hr. In the Sr-containing alloys, enhanced strengthening was also associated with increased dislocation resistance in the presence of stacking faults. The trace additions of Sn or Sr, combined with two-step aging, offer a cost-effective strategy for developing the next generation of thermally stable, high-performance conductor alloys.
This study examines the role of microstructural heterogeneities in controlling tensile ductility in structural high-pressure vacuum die-cast (HPVDC) AlSi10MnMg (AuralTM-2) aluminum alloy. Two variants produced under similar processing conditions displayed markedly different ductility levels. Tensile specimens were extracted from multiple locations along the casting—from ingate to overflow—to evaluate spatial variations in mechanical properties. The typical (high-ductility) variant exhibited strong position-dependent elongation, increasing from 8
Maintaining thermal balanceThermal balance in aluminum electrolysis cellsAluminum electrolysis cell is essential for operational stability, energy efficiencyEnergy efficiency, and process longevity. This balance is affected by thermal events from normal operations and anomalies such as anode effectsAnode Effect (AE). A key indicator is the spatial and temporal evolution of the ledge which is highly sensitive to thermal fluctuations. While previous studies focused on shell temperatureShell temperature and ledge tracking, few have addressed characterizationCharacterization and detection of thermal events. This study aims to characterize thermocouple signals associated with thermal events, particularly anode changesAnode change. Using a combination of signal processingProcessing and machine learningMachine learning, specifically k-means clusteringClustering, distinct thermal patterns were identified. Data were collected from a fully instrumented industrial cell and processed through feature extractionExtraction and selection. The findings were validated by an analog model and a full-scale industrial cell. This method demonstrated reliable pattern recognition and opens new avenues for process controlProcess control, predictive maintenance, and operational efficiencyOperational efficiency.
