Book Chapters

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Browsing Book Chapters by browse.metadata.cluster "Manufacturing"

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    Characterisation of additive manufactured Ti6Al4V-W–Ni composite
    (Cham: Springer, 2024-11) Mahamood, RM; Akinlabi, S; Jen, TC; Pityana, Sisa L; Omoniyi, P; Arthur, Nana KK; Akinlabi, ET; Da Silva, LFM
    Excellent properties of titanium alloy grade V make this alloy a material of choice in aerospace industry and other industries such as biomedical and medical industries. The most attractive of these properties for the aerospace industry is the high-strength-to-weight ratio. The need for advanced materials that are designed to produce a set of properties that cannot be seen in a single material is constantly needed in various engineering applications. Additive manufacturing (Am) technology is central to achieving this goal because of the possibility of producing any component using the desired material in a single manufacturing run and as a single component no matter the complexity of the part. In this study, the microstructural evolution and mechanical property of Ti6Al4V-W–Ni composite produced through laser metal deposition, an additive manufacturing technology, was investigated. Elemental powder of nickel and tungsten powder were deposited on titanium alloy grade V substrate by varying the laser scanning speed from 0.12 m/mm to 0.48 m/min, while keeping all other processing parameters constant. The effect of scanning speed on the evolved microstructure and microhardness were studied. Functionally gradient microstructures were observed in all the samples with varying microhardness values. As the scanning speed was reduced, high microhardness was observed. All samples produced have higher microhardness values than the substrate material. Samples produced at a scanning speed of 0.3 m/min has the highest average microhardness value of 491.8. This study revealed that AM can be used to produce complex part with designed material properties in a single manufacturing run.
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    Recent advances of high entropy alloys: High entropy superalloys
    (IntechOpen, 2021-09) Dada, M; Popoola, P; Adeosun, S; Pityana, Sisa L; Mathe, Ntombizodwa R; Aramide, O; Malatji, N; Lengopeng, T; Ayodeji, A; Kitagawa, J
    This study reviews the recent technological advancements in manufacturing technique; laser surface modification and material; High Entropy Superalloys. High Entropy Superalloys are current potential alternatives to nickel superalloys for gas turbine applications and these superalloys are presented as the most promising material for gas turbine engine applications.
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    Residual stress in laser powder bed fusion
    (Elsevier, 2021-05) Mugwagwa, L; Yadroitsava, I; Makoana, Nkutwane W; Yadroitsev, I; Igor, Yadroitsev, I; Ina Yadroitsava, I; Du Plessis, A; MacDonald, E
    Laser powder bed fusion (L-PBF) has great prospects for biomedical, automotive, aerospace and other high-tech industry sectors due to its manufacturing flexibility and design freedom. However, several factors that include high residual stresses, random porosity and dimensional accuracy can affect the quality of parts and hamper L-PBF progress and widespread industrial applications. Residual stresses are inherent in laser-based processing, and focused studies to control these stresses are topical. Thermal and mechanical post-processing methods, such as stress-relief heat treatment and machining, can relieve residual stresses but cannot reverse in situ stress-induced distortions or cracking. Thus, in situ stress relief remains an attractive option/complement for managing the effect of residual stress on part strength, surface integrity, and dimensional accuracy. Better still, combining in situ and post-processing stress-relief techniques could be a more effective approach to residual stress control. This chapter presents a detailed analysis of the residual stress control techniques that can be applied in L-PBF. Recommendations for effective evaluation and appropriate selection of residual stress management techniques are outlined.