Effect of some consolidation parameters on the microstructure and physicalproperties of a PM-Ni3Al alloy

The aim of this work is to study the viability of using no-destructive tech niques tc study the effect of consolidation parameters in the microstructur e and elastic constants of a PM Ni3Al with molybdenum additions synthesised by rapid solidification and hot isostatic pressing (HIP). Furthermore the homogeneity of the compacts and presence of pores and cracks were evaluated by X-ray. For this purpose, three capsules of the alloy consolidated by HI P at different temperatures, 900, 1100 and 1250 degreesC, have been studied using X-ray techniques, ultrasonic measurements and Eddy-current. Paramete rs such as ultrasonic velocity measurements of longitudinal and transverse waves, the ultrasonic signal attenuation for high frequency, electrical con ductivity and density were determined to evaluate the physical constants Eo , Go y muo, The reflected and reverberation signals have been analysed usin g the Fast Fourier Transformation obtaining for both a frequency spectrum t hat have been interpreted as Acoustic Materials Signature functions. A line al increase of E-o and G(o) with an increases of the consolidation temperat ure has becn measured which has been related to the capsules densification condition, Similar results have been obtained by measuring the electrical c onductivity of the capsules. Thus, the highest value was exhibited by the c apsule hipped at 1250 degreesC indicating that no defects are present and t herefore reaching the optimal consolidation temperature.