In industrial fields, thermal fatigue behavior has recently acquired an important role which is mainly related to the interaction between mechanical and thermal conditions. This paper proposes a thermal fatigue model of H13 tool steel under thermos-mechanical cycles. A test apparatus was used to assess the thermal fatigue resistance of materials to estimate surface crack area when specimens are subjected to thermal cycling. Thermal cycling up to 700°C was used, and crack patterns were examined after 1850, 3000, and 5000 cycles. Temperature distributions were measured at different locations in the test specimens. A model was developed to establish a relationship between mechanical cycling and thermal analysis. From the results, the thermal fatigue resistance was significantly improved over the control parameter after heating and cooling during thermomechanical cycles. The model was applied to determine the best performance and in-service life of die casting tools.

Aims: Remanufacturability Index (RI) was calculated to indicate the ability of remanufacturing conventional shaping into CNC machine tool through multi-criteria assessment methodology. Place and Duration of Study: Middle Technical University, Institute of Technology-Baghdad, Mechanical Techniques School, between 2021/2022. Methodology: Conventional shaping machines which are remanufactured-upgraded into CNC machine tools were analyzed to classify a group of seven remanufacturing-upgrading alternatives. Multi-criteria were defined include cost, time, accuracy and complex shape, reliability, processing range and efficiency and ergonomic. Weighting of importance of criteria and performance of alternatives were conducted by applying comparative literature analysis and machine tool remanufacturing experience analysis of mechanical structure of remanufactured-upgraded conventional shaping into CNC machine tool as well as alternatives performances scoring. Results: As many as the number of automated axes, as high as the Remanufacturability Index (RI) which is dedicated to remanufactured-upgraded conventional shaping into 2-axis to 5-axis CNC machine tool. Conclusion: Remanufactured-upgrading conventional shaping into CNC machine tool is of high remanufacturing potentials that satisfy conditions of technical, economic and environmental feasibilities.