Synthesis of Fe-based amorphous composite coatings with low purity materials by laser cladding

Amorphous composite coatings Fe38Ni30-XSi16B14V2MX (X= 0, 1, 2) (M contains Al, Ti, Mo, and Q were prepared with low purity of raw materials by laser cladding. X-ray diffraction and transmission electron microscopy results show that the coating have an amorphous structure with a few crystalline phase on it. The amorphous phase is the primary phase. The glass forming ability as well as the microhardness of the Fe-based alloy made from low purity raw materials can be much enhanced by adding small amount of multi-components. However, the elements addition has its optimal quantity. When X is equal to 1, the microstructure of the coating contains 97.93% amorphous phase and 2.07% crystalline phase on it. As a result, the microhardness of the coating reaches maximum. With further increasing of the additions, the amorphous phase in the coating lessens instead of augment and the crystalline phase begins to accumulate, which result in the decrease of the microhardness. (c) 2007 Elsevier B.V. All rights reserved.