Thermally Formed Oxide Films on Al–XSi Alloys Heated in Different Gases

Abstract

Thermogravimetric analysis (TGA) testing was used to measure the change in weight of polished samples of Al-XSi (X = 0 and 1.2 mass%) alloys. The samples were heated at 843 K for 6 h in dry air or nitrogen gas. X-ray diffraction was used to monitor the formation of the oxide films on the surface of the samples. The surface oxide films were more compact after the Al alloy samples were heated in air, and the oxide films showed some cracks after being heated in nitrogen gas. The thermally formed surface oxide films on the Al-1.2 mass% Si alloy samples heated in air and in nitrogen gas possessed loose structures, which comprised mainly c-alumina, diaspore, and gibbsite, along with metallic silicon and/ or aluminum. The weight variation curve of the films appeared serrated; this can be attributed to chain reactions (3Si + 3O 2 ? 3SiO 2 + 4Al ? 3Si + 2Al 2 O 3 ) that occurred within the film.

Role of Interface(s) for the Growth of Ultra‐Thin Amorphous Oxides on Al–Si Alloys: A Thermodynamic Analysis

“…Finally, the segregation of silicon from the bulk of the Al–Si binary alloys (and/or Al–Mg–Si ternary alloys) to the alloy/oxide interface during dry, thermal oxidation was not observed experimentally in the literature which is in agreement with the present thermodynamic prediction (see Section and Fig. ) …”

Preparation and characteristics of polymer matrix composite coatings with low infrared emissivity and high‐temperature resistance

“…This also prevented further oxidation of the internal aluminum. [37,38] When the temperature reached 590 C, the weight gain of the aluminum powder increased rapidly due to the destruction of the oxide layer. In addition, PPENK and the composite coating exhibited excellent thermal stability with T d5% of 493 C and 506 C, respectively.…”