Aplicação de micro-ondas para a produção de pós usados em revestimentos endurecidos por carbonetos de titânio formados durante soldagem com arco elétrico GTAW
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Data
2019-08-08
Autores
Lomba Filho, Luiz Gustavo Freddi
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Universidade Estadual Paulista (Unesp)
Resumo
As superfícies desgastadas são normalmente revestidas com ligas metálicas resistentes ao desgaste abrasivo, nos quais durante a soldagem o metal de solda com matriz ferrosa é reforçado pela formação de carbonetos grosseiros durante a solidificação da poça de fusão. O propósito deste trabalho é investigar a aplicação de micro-ondas para o preparo de cavacos das ligas de titânio ASTM F67 e ASTM F136, visando a sua fragilização pela formação de uma fina camada de carbonetos que facilitam a moagem e a obtenção de pós finos. O pó obtido da reciclagem do titânio foi misturado com grafite, tornando possível a formação de carbonetos de titânio (TiC) durante a fusão da mistura sobre peças de aço-carbono ABNT 1020 com uma tocha a arco elétrico com proteção gasosa (GTAW). A aplicação de micro-ondas foi bem sucedida, permitindo a obtenção da mistura carbonetante com granulometria inferior a 45m. O metal de solda mostrou uma microestrutura ferrítica reforçada por partículas grosseiras TiC, que incrementaram significativamente a dureza do material. Os resultados obtidos indicam que a reciclagem de cavacos de titânio seja potencialmente interessante para o desenvolvimento de um consumível de soldagem para revestimentos resistentes ao desgaste abrasivo, mais econômico e ambientalmente sustentável.
The worn surfaces are usually coated with abrasive resistant metal alloys, where the weld metal is reinforced by the formation of coarse hard carbides during the melt pool solidification. The aim of this work is investigate the irradiation of microwaves on scrap (chips) of ASTM F67 and ASTM F136 titanium alloys, becoming easier grinding of the residues for obtaining fine powder due to chips embrittlement by thin TiC coating. The titanium-rich recycled powder was mixed with graphite, making possible the formation of titanium carbides (TiC) during the melting of the mixture by Gas-Tungsten Arc Welding (GTAW) carried out on ABNT 1020 carbon steel pieces. The microwave application was very successful, allowing to obtain a fine carbide-former mixture with granulometry less than 45m. The weld metal have showed a microstructure composed by ferrite (BCC iron) reinforced by coarse dendritic TiC particles, which promoted significantly hardness increasing. The experimental results have indicate that microwave irradiation for titanium alloys chips recycling is potentially interesting for the development of a economical and environmentally sustainable consumables for abrasive wear resistant hardfacing.
The worn surfaces are usually coated with abrasive resistant metal alloys, where the weld metal is reinforced by the formation of coarse hard carbides during the melt pool solidification. The aim of this work is investigate the irradiation of microwaves on scrap (chips) of ASTM F67 and ASTM F136 titanium alloys, becoming easier grinding of the residues for obtaining fine powder due to chips embrittlement by thin TiC coating. The titanium-rich recycled powder was mixed with graphite, making possible the formation of titanium carbides (TiC) during the melting of the mixture by Gas-Tungsten Arc Welding (GTAW) carried out on ABNT 1020 carbon steel pieces. The microwave application was very successful, allowing to obtain a fine carbide-former mixture with granulometry less than 45m. The weld metal have showed a microstructure composed by ferrite (BCC iron) reinforced by coarse dendritic TiC particles, which promoted significantly hardness increasing. The experimental results have indicate that microwave irradiation for titanium alloys chips recycling is potentially interesting for the development of a economical and environmentally sustainable consumables for abrasive wear resistant hardfacing.
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Reciclagem de titânio, Irradiação de micro-ondas, Processos de soldagem, Carbonetos de titânio, Revestimento, Caracterização microestrutural, Titanium recycling, Titanium carbides, Microwave irradiation, GTAW, Hardfacing, Microstructural characterization