September 26, 2018
Source: ASM International
Mipar Software, Worthington, Ohio, announces that it has developed a software package called Mipar that enables engineers to quantify the size distribution and volume fraction of gamma-prime Ni3Al precipitates in nickel-base superalloys. Nickel-base superalloys are extensively used in high-temperature, high-stress applications. The presence of coherent γ′-Ni3Al precipitates provides the requisite elevated temperature strength and creep resistance in these alloys.
Therefore, quantification of the precipitate size distribution and volume fraction is essential for accurate model predictions and future alloy design. Current γ′ volume fraction characterization techniques lack precision and repeatability. Without a reproducible procedure, unacceptable variations and errors have plagued the past six decades of superalloys research and have inhibited the implementation of accurate precipitation models for these alloys.
Through the use of high resolution, low kV, scanning electron microscopy pioneered at NASA, and state-of-the-art image post-processing, a new, accurate γ′ characterization technique has been developed, and will be demonstrated at MS&T 2018 (booth 407). Using the new technique, secondary γ′ volume fractions in superalloy ME3 were calculated, and confirmed through phase extraction, thus opening the possibility for validation of presently used superalloy precipitation databases.
Using Mipar, along with a new imaging technique, NASA overcame barriers to accurate image analysis that had frustrated the aerospace materials community for decades. This led to published methods which NASA has proposed as a new standard for nickel superalloy analysis.
Link to Paper: https://www.sciencedirect.com/science/article/pii/S1044580318304716
Industries and Applications | Aerospace and Defense
Industries and Applications | Fossil Fuel Power
Materials Properties and Performance | Mechanical Properties
Metals and Alloys | Superalloys, Nickel, and Cobalt