Models have been developed and used as tools to design a new `made to measure’ nickel base superalloy for power plant applications. In Part 1 Gaussian processes were used to model the mechanical properties of superalloys, and have been used as a basis for the design of a new Ni ± Cr ± W ± Al ± Ti ± Fe ± Si ± C ± B superalloy with desirable properties. In this part, an attempt has been made to d...

Grain segmentation on 3D superalloy images provides superalloy’s micro-structures, based on which many physical and mechanical properties can be evaluated. This is a challenging problem in senses of (1) the number of grains in a superalloy sample could be thousands or even more; (2) the intensity within a grain may not be homogeneous; and (3) superalloy images usually contains carbides and nois...

Vari.ous methods available for the exploitation of atom-probe concentrat ion prof iles are discussed. T h e determinat ion of microstructure Parameters of a nickel base superalloy containing small precipitates is given a s an example.

The causes of liquation cracking in the heat-affected zone (HAZ) of a cast Mar-M004 superalloy weld were investigated. X-ray diffraction (XRD), electron probe microanalyzer (EPMA), and electron backscatter diffraction (EBSD) were applied to identify the final microconstituents at the solidification boundaries of the cast alloy. Fine borides and lamellar eutectics were present in front of some γ...

Laser additive forming is considered to be one of the promising techniques to repair single crystal Ni-based superalloy parts to extend their life and reduce the cost. Preservation of the single crystalline nature and prevention of thermal mechanical failure are two of the most essential issues for the application of this technique. Here we employ synchrotron X-ray microdiffraction to evaluate ...

This study investigated the effects of the hot isostatic pressing process on the crack healing, microstructure, and mechanical properties of the laser repair-welded CM247LC precipitation-hardened superalloy. To ensure the strength of the repair-welded area, this study used the direct re-melting approach, and simulated the repair welding with the filler addition, which has a chemical composition...

K465 superalloy with high titanium and aluminum contents was easy to crack during laser metal deposition. In this study, the crack-free sample of K465/Stellite-6 laminated material was formed by laser metal deposition shaping to control the cracking behaviour in laser metal deposition of K465 superalloy. The microstructure differences between the K465 superalloy with cracking and the laminated ...

Convective instabilities responsible for misoriented grains (freckle defects) in directionally solidified turbine airfoils are produced by variations in liquid–metal density with composition and temperature across the solidification zone. Here, fundamental properties of molten Ni-based alloys, required for modeling these instabilities, are calculated using ab initio molecular dynamics simulatio...

As shown in the preceding chapter, simple binary eutectic Ni-Hf and Ni-Zr braze alloys can be used to successfully join In738 Ni-base superalloy. The joint gap must, however, be narrow (less than 0.15 mm in width) to allow capillary action to draw the filler metal into the joint. Such narrow joint gaps are usually only found in the manufacturing industry. In the repair industry, especially in I...

The effects of microstructures during creep on the ultrasonic attenuation have been investigated for Ni based superalloy (IN738LC). The cuboidal γ′ precipitates in the virgin material became coarsened preferentially in the direction perpendicular to the applied stress axis as creep time increased. The length of γ′ precipitates increased with creep time, while the width increased slightly. The i...