Investigation of Microstructure of Ni-Al Bronze (C95520) During Heat Treatment - CANCELLED

Abstract

 

Cast Ni-Al bronze (C95520) has a complex microstructure. As, the microstructure of this alloy can be considerably changed during heat treatment.  Hence, heat treated samples (C95520) were studied by using scanning electron microscopy (SEM), Field emission  scanning electron microscopy (FESEM) equipped with energy dispersive spectrometer (EDS), X-Ray diffraction analysis and micro-hardness. This alloy was heat treated at different times and temperatures. As, in the quenched specimens with enhancement of temperature of heat treatment, α grains with nonlinear boundaries (Widmanstatten) were transformed to larger polygonal grains with linear boundaries. On the other hand, normalized samples contained wide and elongated α Phase. As, the size of κ₁ and κ₂ phases was larger in comparison with κ₁ and κ₂ phases in the quenched samples with increasing the temperature of heat treatment. The α grain in the normalized samples with the increasing the temperature of heat treatment became polygonal with linear boundaries and larger in comparison with α grains in the quenched samples. Less β phases were observed in the normalized samples due to severe phase transformation of β to α+γ₂ at elevated temperatures. On the other hand, the quenched samples showed more hardness in comparison with normalized samples.

Key words: Heat treatment of nickel aluminum bronze alloy, Kapa phases, Widmanstatten phases, normalized samples, quenched samples