Analysis of Chemical, Microstructural and Mechanical Properties of a CuAlBe Material Regarding Its Role as a Non-Sparking Material.

We developed and analyzed a novel non-sparking material based on CuAlBe for applications in potentially explosive environments. Using a master alloy of CuBe, an established material for anti-sparking tools used in oil fields, mines, or areas with potentially explosive gas accumulations, and pure Al, we used an Ar atmosphere induction furnace to obtain an alloy with ~10 wt% Al and ~2 wt% Be percentages and good chemical and structural homogeneity. The new material was tested in an explosive gaseous mixture (10% H2 or 6.5% CH4) under extremely strong wear for 16,000 cycles, and no hot sparks capable of igniting the environment were produced. The material was used in the form of hot-rolled plates obtained from melted ingots. The experimental results reflect the use of a suitable material for non-sparking tools. This material has good deformability during hot rolling, abnormal grain growth during deformation under heat treatment and special thermo-mechanical processing, and no high chemical composition variation. Additionally, there are slightly different corrosion resistance and mechanical properties between the melt and hot-rolled state of CuAlBe material. Through hot rolling, the material's corrosion resistance increased, reducing the chances of generating sparks capable of causing explosions.

Microstructural, Corrosion Resistance, and Tribological Properties of Al2O3 Coatings Prepared by Atmospheric Plasma Spraying.

An usual material, EN-GJL-250 cast iron, used for automotive braking systems, was covered with a ceramic material (105NS-1 aluminium oxide) using an industrial deposition system (Sulzer Metco). The main reason was to improve the corrosion and wear (friction) resistance properties of the cast-iron. Samples were prepared by mechanical grinding and sandblasting before the deposition. We applied two and four passes (around 12-15 µm by layer) each at 90° obtaining ceramic coatings of 30 respectively 60 µm. The surface of the samples (with ceramic coatings) was investigated using scanning electron microscopy (SEM), dispersive energy spectroscopy (EDS) and X-ray diffraction (XRD). Scratch and micro-hardness tests were performed using CETR-UMT-2 micro-tribometer equipment. The better corrosion resistance of the base material was obtained by applying the ceramic coating. The results present a better corrosion resistance and a higher coefficient of friction of the coated samples.