Author(s)

A.M. Hashem

Abstract

Rate of growth of wedge type intercrystalline creep micro-cracks of nickel aluminide alloys A.M. Hashem Production Eng. & Design Dept., Faculty of Engineering, Minia University, Egypt Abstract Under high temperature creep is active. Intercrystalline creep micro-cracks takes place due to the initiation and growth of intercrystalline cavities. Polycrystalline nickel aluminide with boron alloy was investigated. This alloy was produced by powder metallurgical using Hot Isostatic Pressing (HIP). Various heat treatments were used to produce different initial grain size. The grain sizes were 20.7, 21.05, 101.5 and 106.0 p.m. The micro- cracks has been studied after creep fracture at a temperatures of 800, 850 and 900 °C and a stress levels of 20 to 90 MPa. The creep fracture surfaces of longitudinal section of specimens which exhibited creep were examined by using an image analysis system. The growth rate, length, thickness and area of the micro-crack of the fractured speci

Keywords