This research focuses on the hardness of gray cast iron. Hardness is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. The machinability cannot set a specific definition. However, several indicators and directories give a clear image, the most important of which is the factors that affect the machinability of gray cast iron according to the metallurgies and the metal cutting and cutting conditions. The main goal of this research is to improve the hardness of gray cast iron. Many experiments on several samples to get different results and then compare these results to get the best which is the goal of the research. The conclusions through the practical side of this research are the different values of hardness through the different hardening processes. As the hardening processes gave a sample of grey cast iron a hardness value that differs in each type of hardening. The notes through the graph that the hardness reaches its peak in the traditional hardening, where its value is (370.6), followed by the laser hardening process, which reaches (321.6) The amount of increase between the hardness of the laser and the traditional hardness takes the value of (15.24 %) The work on samples in the form of aggregates, and each group will be treated in a specific way and then subject to tests.

Aluminum alloys were widely used in the construction, automotive, marine, and aviation industries due to their low specific strength, ease of manufacture, and low weight. The fatigue behavior of aluminum alloys at different temperatures is investigated. Thanks to the rapid development of armament in recent years, 7XXX ultra-high strength aluminum alloys are now used more frequently because of their non-corrosive qualities and low weight. Aluminum alloy 7001-T6 behavior is examined at the Company State for Engineering, Rehabilitation, and Inspection (SIER) in Iraq, where chemical analysis of the AA7001 is supported. Most engineering components that operate at high temperatures will eventually fail from fatigue strain, creep damage is a time-dependent process that is primarily influenced by the history of stress and temperature applied to the component. When the two damaging factors combine their effects, This study used AA7001-T6 to conduct experiments on mechanical characteristics (UTS, YS, E, and ductility) and the interaction between creep and fatigue at four distinct temperatures: room temperature (25, 150, 280, and 330) °C, the UTS, YS, and E were lowered by 37.2, 37.2, and 24) %, respectively, as compared to the result at room temperature, but the ductility increased by 28.27 %. It has been noted that rising temperatures cause mechanical and fatigue characteristics to decline. Experimental S-N fatigue test findings showed a significant loss of fatigue strength, After 107cycles, the endurance fatigue limit was reduced from 208 MPa at (RT) to 184 MPa at 330 °C, an 11.5 % reduction. Overall, it can be said that AA7001-T6 demonstrates a significant drop in mechanical and fatigue properties at high temperatures