Institute of Fundamental Technological Research

The paper presents the results of studies on the structure and properties of the AlNi type diffusion layers fabricated on the IN 740 nickel alloy by chemical vapor deposition using aluminium chloride (AlCl3), introduced into a hydrogen atmosphere. The layers were examined by light microscopy and scanning electron microscopy. Their chemical composition was examined by EDS, and the phase composition - using a Bruker D8 X-ray diffractometer with CuKa radiation. Fatigue tests were carried out in Inconel 740 sample, in the initial state and covered with the diffusion intermetallic AlNi layers. The strength under dynamic load was examined using a MTS 858 testing machine using symmetric load cycles repeated at a frequency of 20 Hz. The stress amplitude was 550 MPa. Corrosion resistance tests were performed employing potentiodynamic methods, in 0.1M Na2SO4 solution, at ambient temperature. It is shown that the layers improve the fatigue resistance and corrosion resistance of the Inconel 740 substrate.

Inconel 740, CVD, Aluminide layer, High-cycle fatigue, corrosion resistance