Preparation of Al-based amorphous coatings and their properties

Al86Ni8Co1La1Y2Gd2 amorphous coatings were prepared using cold gas kinetic spray technology. The results show that Al86Ni8Co1La1Y2Gd2 amorphous coatings are achieved with the porosity about 3.2%, thickness about 893 mu m, the amount of amorphous phase about 82.5%, the hardness about 300HV(0.2). The corrosion potential and anti-corrosion life of 7075 T6 alloy aluminum are about -0.78 V and 72 h, respectively. The electrochemical analysis and neutral salt spray are about -0.69 V corrosion potential and 274 h anti-corrosion life for amorphous Al-based coatings, respectively. Therefore, the life of the Al-based amorphous coatings is about 3.8 times that of 7075 T6 aluminum alloy. Besides, the failure mechanism was analyzed using TEM in this investigation. In a word, Al86Ni8Co1La1Y2Gd2 coatings keep dense structure, high amorphous content, favorable amorphous phase stabilizing ability and longer anticorrosion life. That is, Al86Ni8Co1La1Y2Gd2 coatings have better comprehensive properties. Therefore, these findings indicate that the present Al86Ni8Co1La1Y2Gd2 amorphous coatings prepared using cold gas kinetic spray technique can protect aluminum alloy very well and they can be considered to be used in aviation field. (C) 2020 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.