Stress gradients in CrN coatings

Stress in hard films is the net sum of tensile stress generated at the grain boundaries, compressive stress due to ion peening, and thermal stress due to the difference in thermal expansion of the coating and substrate. The tensile part due to grain boundaries is thickness dependent. The other two contributions are not thickness dependent....

Tensile stress in hard metal films

Thin films on substrates are usually in a stressed state. An important, but trivial, contribution to that stress stems from the difference in thermal expansion coefficient of substrate and film. Much more interesting are the intrinsic stresses, resulting from the growth and/or microstructure of the film. Intrinsic compressive stress was...

Tensile fracture of notched composite laminates

This report describes the determination of empirical parameters for a fracture model which can be used to predict the uniaxial tensile strength of composite laminates containing notches of various sizes. The parameters required are the characteristic dimension and the unnotched tensile strength of the subject laminate. A data base including...

Heat treatment studies of aluminium alloy type 7050 forgings. Interim report no. 2: The effect of heat treatment on a variety of engineering properties

The effect of variety of heat treatments on various engineering properties was studied with the aim to derive an optimum heat treatment. The engineering properties comprised Vickers hardness, short-time tensile strength, fatigue crack propagation resistance, fracture toughness and stress corrosion resistance. The test results were compared with...

Tensile failure of unidirectional composite materials