Picture of boy being examining by doctor at a tuberculosis sanatorium

Understanding our future through Open Access research about our past...

Strathprints makes available scholarly Open Access content by researchers in the Centre for the Social History of Health & Healthcare (CSHHH), based within the School of Humanities, and considered Scotland's leading centre for the history of health and medicine.

Research at CSHHH explores the modern world since 1800 in locations as diverse as the UK, Asia, Africa, North America, and Europe. Areas of specialism include contraception and sexuality; family health and medical services; occupational health and medicine; disability; the history of psychiatry; conflict and warfare; and, drugs, pharmaceuticals and intoxicants.

Explore the Open Access research of the Centre for the Social History of Health and Healthcare. Or explore all of Strathclyde's Open Access research...

Image: Heart of England NHS Foundation Trust. Wellcome Collection - CC-BY.

On the applicability of JMAK-type models in predicting IN718 microstructural evolution

Stefani, Nicola and Bylya, Olga and Reshetov, Aleksey and Blackwell, Paul (2017) On the applicability of JMAK-type models in predicting IN718 microstructural evolution. Computer Methods in Materials Science, 17 (1). pp. 59-68. ISSN 1641-8581

Text (Stefani-etal-CMMS-2017-On-the-applicability-of-JMAK-type-models)
Final Published Version

Download (3MB) | Preview


Nickel-based superalloys are widely used in the aerospace sector for their mechanical properties, which are directly related to the microstructural and physical properties of these materials. JMAK-type models have been applied to this class of superalloys for the prediction of microstructural evolution phenomena such as recrystallisation. However, these models often lack a clear range of applicability. The majority of the successful applications normally address rather idealised processes (relatively slow forging, simple geometry). However, the industrial production environment generally involves complex strain paths and thermal histories. Thus, there arises the question of whether the JMAK-type models can be applied to such cases. This paper’s research focus is to investigate the applicability of JMAK-type models for such processes. To do this, screw press forging of disks was used to validate the in-built JMAK-type model of Inconel 718® available in DEFORMTM. In particular, the applicability of the model was examined using a comparison between the results from simulation and from metallographic analysis. At first, the appropriateness of the JMAK outputs in describing the observed microstructures was investigated and then quantitative results were evaluated. The model’s outputs were found to be insufficient in describing the observed microstructural states and additional parameters were deemed necessary. The model’s predictions ranged from a broadly good match, for which the model could be calibrated with a proposed new methodology, to a qualitative mismatch that highlights the limits of the model’s applicability.