No abstract

The use of NiCrAlY is a great alternative as Bond Coat - BC (bonding layer) in coatings for turbine vane, and it is possible to increase its life. This work aims to study the BC layer of NiCrAlY on the substrate of 316 steel which was deposited by the High Velocity Oxygen Fuel method (HVOF) and after laser remelting irradiated. selective laser melting which is an innovative process. The laser treatment induced changes in porosity, microhardness and wear resistance. After spraying, the samples were irradiated with a CO2 laser beam by varying the scan speed in 50, 100 e 200 mm/s. The speed at which the metallurgical bond between the coating and the substrate occurred was of 50 mm/s. A wear test was performed to analyze the thickness of the coating, which was 60 μm, and the hardness profile and hardness profile where it presented a higher hardness in the coating after the laser treatment. The investigations range included analysis of top surface of coatings by XRD characterization oxides formed types and microscopic investigations of coatings morphology.

<p>As indústrias siderúrgicas brasileiras geram, em média, 145 mil toneladas por mês de areia descartada de fundição (ADF) ou resíduos de areia de fundição (RAF), como um subproduto do processo de fundição, impactando meio ambiente, sociedade, as próprias siderurgias e aterros sanitários. Porém, por ser considerado um resíduo não perigoso e muito semelhante aos agregados minerais, seu reuso na construção civil se mostra como uma interessante alternativa, evitando os impactos do descarte, além de beneficiar financeiramente as infraestruturas construídas. Nesse contexto, este artigo objetivou a dedução de uma rota metodológica para contabilizar esta economia gerada e estimar, em termos de economia financeira e de bens ambientais, os benefícios gerados no Brasil e no município de João Pessoa, estado da Paraíba, como um estudo de caso. Dessa forma, uma equação foi obtida, abrangendo diversos aspectos da cadeia de produção e descarte de ADF/RAF, estimando economias da ordem de 500 milhões de USD anuais, além de redução de emissões de CO₂ equivalente ao consumo de mais de 10 mil veículos por ano; pelo reuso da ADF/RAF produzida no Brasil.</p>

No abstract

The main objective of this work is to study and characterize porous ZrO2-TiO2 films on alumina substrates that will be used for the production of porous ceramic sensors for the monitoring of air humidity in environments subject to the incidence of solar radiation. For the production of the films the dip coating technique was adopted. A viscosity study was performed to obtain stable suspensions of ZrO2-TiO2 in isopropyl alcohol with the para-aminobenzoic acid deflocculant (PABA), at concentrations of 10, 12.5 and 15% by weight of solids. X-ray diffraction (XRD) characterizations were performed for the identification of crystalline phases, morphological analyzes by scanning electron microscopy (SEM) and chemical analyzes by energy dispersive X-ray spectroscopy (EDS). The results allowed to determine the minimum value of viscosity and amount of deflocculant to stabilize the suspension. The sensor elements in the form of 1:1 (weight) ZrO2 - TiO2 porous films showed great potential to be used as sensors for the measurement of relative humidity the size and distribution of desirable pores in the porous film for application as moisture sensors was obtained with 12.5 and 15 % by weight ZrO2-TiO2