Strengthening Mechanisms in NiAl Bronze: Hot Deformation by Rolling and Friction-Stir Processing

Abstract

Microstructures produced by isothermal hot rolling of a NiAl bronze material were evaluated by quantitative microscopy methods and parameters describing the contributions of precipitate dispersions, grain size, solute content, and dislocation density to the yield strengths of the individual constituents of microstructure were determined. Models for the strengths of the individual constituents were combined to predict the temperature dependence of the yield strength as a function of hot rolling temperature, and the prediction was found to be in good agreement with measured yield strengths. The models were applied to microstructures in a stir zone produced by multipass friction-stir processing (FSP) and, again, found to predict measured yield strengths with high accuracy. Such models may aid in assessing the role of microstructure gradients produced during FSP and other processes.

Influence of friction stir process parameters on surface quality of aluminum alloy A2017

“…This is one of major advantages of friction stir processing, because it allows finishing the surface and, in the meantime, it applies in-situ localized heat treatment leading to microstructural refinement, densification, homogeneity, increased microhardness, superior wear and corrosion resistance of the surface layer. Friction stir was initially applied to aluminium alloys [1] and extended lately to other materials such as copper alloys [4,5], magnesium alloys [6,7], steels [8,9] or titanium alloys [10,11].…”

Investigation of microstructure and mechanical properties of hot worked NiAl bronze alloy with different deformation degree

“…In addition, the strengthening mechanisms of deformed NAB alloy have been investigated in many literatures [15,16]. Ni et al [17] found that dynamic recrystallization occurred in the stir zone during FSP.…”

“…Ni et al [17] found that dynamic recrystallization occurred in the stir zone during FSP. Menon et al [16] investigated the strengthening mechanisms in NAB alloys and established the models of hot rolled NAB. Su et al [15] found that the equiaxed α grains were produced during FSP as the local equivalent strains exceed 2.5.…”

Strengthening mechanism of friction stir processed and post heat treated NiAl bronze alloy: Effect of rotation rates

“…The applications of friction stir processing on NAB alloy have been reported in many studies [13][14][15][16]. Oh-ishi et al reported that highly refined and recrystallized grains with grain size of 2 μm were formed in friction stir processed NAB alloys.…”