Measurement of fracture toughness of nickel phosphorus coatings

The fracture toughness of the electroless nickel phosphorus coatings have been measured using a notched tensile specimen made of the film, which was stripped along the interface between outer and inner layers of the coatings. The results showed that the average fracture toughness of as-deposited NiP amorphous coatings was K-IC=7.1 MPa m(1/2) and decreased with increasing heat treatment temperature. For example, K-IC = 5.2 MPa m(1/2) for a 300 degrees C treatment, K-IC=3.7 MPa m(1/2) for a 330 degrees C treatment and K-IC= 1.2 MPa m(1/2) for a 400 degrees C treatment corresponding to complete crystallization. (c) 2005 Elsevier B.V. All rights reserved.