Browsing by Author "Dimitrov, Dimiter"

Now showing 1 - 4 of 4
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    Cluster development in the SA tooling industry
    (SAIIE, 2015) Von Leipzig, Konrad; Dimitrov, Dimiter
    This paper explores the concept of clustering in general, analysing research and experiences in different countries and regions, and summarising factors leading to success or contributing to failure of specific cluster initiatives. Based on this, requirements for the establishment of clusters are summarised. Next, initiatives especially in the South African tool and die making (TDM) industry are considered. Through a benchmarking approach, the strengths and weaknesses of individual local tool rooms are analysed, and conclusions are drawn particularly about South African characteristics of the industry. From these results, and from structured interviews with individual tool room owners, difficulties in the establishment of a South African tooling cluster are explored, and specific areas of concern are pointed out.
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    Investigating components affecting the resource efficiency of incorporating metal additive manufacturing in process chains
    (Elsevier, 2017) Girdwood, Richard; Bezuidenhout, Martin; Hugo, Philip; Conradie, Pieter; Oosthuizen, Gert; Dimitrov, Dimiter
    ENGLISH ABSTRACT: Pursuing more sustainable process chains, manufacturers are constantly striving to enhance the resource efficiency of their manufacturing processes. As part of this, additive technologies have become increasingly important for reducing waste, time and costs. Various input factors affect the efficiency of an additive approach and therefore also have an impact on the sustainability. Towards the establishment of an evaluation framework, this paper investigates the components that influence the resource efficiency of additive process chains. An overview is provided on the different approaches and techniques that have been used with the aim of identifying the most influential factors. The framework was validated using a titanium aerospace benchmark component and thereby proved its ability to assist the process planners with decisions regarding process chain selection.
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    Investigation of the effect of scan vector length on residual stresses in selective laser melting of maraging steel 300
    (Southern African Institute for Industrial Engineering, 2019) Mugwagwa, Lameck; Dimitrov, Dimiter; Matope, Stephen; Yadroitsev, Igor
    ENGLISH ABSTRACT: Selective laser melting scanning strategies influence the quality characteristics of parts, such as form accuracy and residual stresses. Previous research on the effect of laser scanning strategy parameters (such as scan vector length) demonstrates that residual stresses decrease with scan vector length reduction. However, most of these studies overlook the associated porosity and how this can contribute to stress relief. In this work, three scan vector lengths were compared to evaluate their impact on residual stresses, achievable part density, and scanning time. Reducing the scan vector length generally lowers residual stresses magnitudes, but introduces porosity as a result of localised overheating.
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    Investigation of the effect of scan vector length on residual stresses in selective laser melting of maraging steel 300
    (Southern African Institute for Industrial Engineering, 2019-12-12) Mugwagwa, Lameck; Dimitrov, Dimiter; Matope, Stephen; Yadroitsev, Igor
    ENGLISH ABSTRACT: Selective laser melting scanning strategies influence the quality characteristics of parts, such as form accuracy and residual stresses. Previous research on the effect of laser scanning strategy parameters (such as scan vector length) demonstrates that residual stresses decrease with scan vector length reduction. However, most of these studies overlook the associated porosity and how this can contribute to stress relief. In this work, three scan vector lengths were compared to evaluate their impact on residual stresses, achievable part density, and scanning time. Reducing the scan vector length generally lowers residual stresses magnitudes, but introduces porosity as a result of localised overheating.