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Gilmar Masiero,Priscila Helena Lee,João Eduardo Albino Pimentel 한국 포르투갈-브라질 학회 2009 포르투갈-브라질 연구 Vol.6 No.2
The paper reviews five decades of diplomatic, economic and science and technology relations between Brazil and South Korea. The history of political- diplomatic relations can be divided into three distinct stages: a preliminary stage focusing on migration, an intermediary stage in which relations between the countries expanded lasting between the period of economic opening until the Asian crisis and the current stage in the twenty-first century that has consisted in the resumption of talks and the signing of agreements on specific issues. While the Brazilian economy is bigger (US$ 1572.8 billion against US$ 947 billion), its presence in international markets is based on the commercialization of commodities and is smaller than Korea. Brazil is the world’s 24th largest exporter and 28th largest importer. In contrast, South Korea exports industrialized products and ranks 11th and 13th, respectively. Besides the increasing trend of trade between the two countries, subsidiaries of Korean conglomerates have begun operating in Brazil and recently some Brazilian companies have also opened ventures in South Korea. While cooperation in the field of Science and Technology is in an incipient stage, political and diplomatic relations have advanced much more rapidly as a result of the signing of numerous bilateral agreements that support increased trade and the development of science and technology. The paper seeks to show that the distinct industrialization paths taken by the two countries has impacted their trade and investment relations and presents an opportunity for greater bilateral cooperation in the field of science and technology.
Residual Stress Heterogeneity Induced By Powder Metallurgy Gear Manufacturing Chains
Lucas Robatto,Ronnie Rego,Victor Righetti,Gilmar Thim,Anderson Borille 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.2
Powder metallurgy represents an alternative to increase sustainability in the manufacturing of automotive gears, but its potential is hindered by a certain lack of knowledge on surface integrity properties that can impair the gear performance. This study explores the effects of the microstructural differences induced by this chain on the residual stress heterogeneity state of gears. X-ray diffraction methods of macro residual stress mapping and line profile analysis were applied for measurements of gear teeth after subsequent steps of the powder metallurgy and the conventional wrought steel chains. The powder metallurgy chain induced more pronounced heterogeneities than the conventional manufacturing, characterized by non-uniform residual stress distributions along the lead and the involute profiles of gear flanks. These non-uniformities observed after carburizing were traced back to the previous steps, surface densification, sintering and compaction. The residual stress distribution patterns of these steps were compatible with the plasticity dynamics of each manufacturing process. Such surface integrity heterogeneities result in a residual stress gradient along the gears functional surface, exposing particular regions to be more susceptible to fatigue effects.