硬度屈服强度

硬度于屈服强度

1. Introduction Wrought Al–Zn–Mg–Cu alloys are used extensively in aerospace applications due to their high strength-to-density ratio (specific strength). Heat treatment of these alloys involves a solution treatment, subsequent quenching, and finally artificial aging that may involve several stages depending on the desired temper. Aluminum alloy 7010 was developed for applications requiring high strength, high fracture toughness, exfoliation resistance and stress corrosion cracking resistance in thick sections [1]. Quality assurance practices in the aerospace industry usually require tensile tests to be conducted on specimens excised from the aluminum parts [2]. Although this practice yields reliable results, excising the tensile coupons not only is time consuming, but also in some applications, leads to the destruction of the part. Therefore, nondestructive methods to estimate the tensile properties, especially yield stress (σY) and tensile strength (ST), have been of interest to process engineers. One of the most common techniques to estimate yield stress and tensile strength has been hardness testing because of its nondestructive (or semi-destructive) nature, leaving behind only an indentation. Moreover, mechanical data can be gathered quickly without the need for excising samples for testing.