Experimental analysis of crack growth in notched specimen made of Ni{sub}3Al intermetallic alloy

摘要

What has been discussed in the paper is findings of preliminary resistance to fracture tests of cylindrical sharp-notched specimens under axial-tension conditions, as well as results of examining fatigue crack propagation and crack growth rate in components made of Ni{sub}3Al intermetallic alloy with the alloying additions of Cr, Zr, and B. The specimens were subjected to three-point bending. The tests were preceded with structure and micro-hardness examination. The process of cracking is analysed. Several plots to show crack length increments and crack growth rate versus the crack length, the number of stress cycles, and the range of the stress intensity coefficient are included. Electron and optical microscopic examination of fractures of the specimens revealed cleavage-like nature of fracture surfaces and cracking closely related with the structure of the material under examination.