5. Conclusão
5.1. Sugestões para trabalhos futuros
De acordo com os resultados e conclusões apresentados, é possível sugerir melhorias e novas etapas para proceder em sequência deste trabalho, buscando-se a otimização dos mecanismos de sinterização estudados. No entanto, torna-se indispensável a produção de um novo fio em que não haja contaminação por MgO, a fim de se obter resultados quantitativos nas caracterizações supercondutoras.
Com relação à estrutura do fio, a espessura de 2,00 mm (Øexterno – Øinterno) da barreira
de Nb usada no primeiro embutimento do fio supercondutor se mostrou insuficiente para suportar a difusão acentuada do Cu nos perfis a altas temperaturas, tornando-se essencial o uso de barreiras mais grossas para esses tratamentos, ou até a escolha de outro componente metálico menos reativo como barreira de difusão.
Sugere-se também o refinamento do processo de deformação mecânica para que se consiga atingir fios com diâmetro próximos a 1,00 mm, a fim de se avaliar a ação dos tratamentos térmicos na microestrutura de fios que contenham dimensões e reduções percentuais dos componentes mais próximas da realidade das aplicações. Ainda, a análise topográfica por elétrons secundários na microscopia eletrônica de varredura é essencial para o profundo entendimento da ação dos tratamentos na morfologia do pó de MgB2. Com a análise
da porosidade, compactação e conectividade, será possível uma melhor qualificação da eficiência da auto-sinterização do MgB2 e da sua decomposição MgB2 ⇌ Mg + MgB4 nos
perfis a 900ºC/24h e 900ºC/10min+650ºC/1h, respectivamente.
Desejando-se ainda otimizar o efeito da decomposição em trabalhos futuros, o qual mostrou melhor resultado no presente trabalho, recomenda-se o uso de pequenas dopagens de Cu na síntese do pó, visto que a presença de fases Mg-Cu líquidas a altas temperaturas são capazes de promover significativamente a migração de material pela matriz e aumentar ainda mais a conectividade granular (CHENG et al., 2017).
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