Effects of adding Ni and Co on microstructure and gamma prime phase stability in Ni superalloy Inconel 738 with 1 wt.-% Al

The effects of adding nickel and cobalt to Inconel 738 along with adding 1 wt.-% of aluminum were investigated in this study. The alloys, with various amounts of nickel and cobalt, were prepared using a vacuum arc melting process. The alloys were heat treated using a standard heat treatment procedure which consisted of solution treatment at 1448 K for 14.4 ks and precipitation aging at 1118 K for 86.4 ks. Increased nickel content was shown to enhance the stability of gamma prime particles and the gamma matrix as well as assist the formation of gamma prime particles. In the case of the addition of cobalt, the coarsening rate of gamma prime particles decreased with increasing cobalt content. Furthermore, a further addition of aluminum to Inconel 738 resulted in an increase in the area fraction of the gamma prime phase and more rapid growth of gamma prime particles during long-term heating compared to standard Inconel 738.

Pathophysiological Basis of Endometriosis-Linked Stress Associated with Pain and Infertility: A Conceptual Review

Women with endometriosis are often under stress due to the associated pain, infertility, inflammation-related and other comorbidities including cancer. Additionally, these women are also under stress due to taboos, myths, inter-personal troubles surrounding infertility and pain of the disease as well as due to frequent incidences of missed diagnosis and treatment recurrence. Often these women suffer from frustration and loss of valuable time in the prime phase of life. All these complexities integral to endometriosis posit a hyperstructure of integrative stress physiology with overt differentials in effective allostatic state in women with disease compared with disease-free women. In the present review, we aim to critically examine various aspects of pathophysiological basis of stress surrounding endometriosis with special emphasis on pain and subfertility that are known to affect the overall health and quality of life of women with the disease and promising pathophysiological basis for its effective management.

The Influence of Nitrogen versus Hydrogen Diluting Gas on the Compound Layer Phase Formation during Ammonia Gas Nitriding of Iron and Low Alloy Steel

In many large industrial furnaces, atmospheric ammonia gas nitriding processes use nitrogen as the diluting gas for safety, economic, and environmental reasons. The widely published Lehrer diagram for ammonia/hydrogen gas nitriding of pure iron serves as a reference guide for selecting ammonia/gas mixtures for nitriding of alloy steels, though the diagram is not precise or accurate when the diluting gas is not hydrogen. Current data reveals that nitrogen shifts the Lehrer diagram phase boundaries to the left. This is pertinent to the topic when only the alpha (α) or gamma prime phase (Fe4N) is desired, not epsilon (Fe2-3N).