As we all know, 7075 aluminum can be heat treated high-strength alloy material, its main alloying element is metal zinc. The most commonly used field of this material is the aerospace industry. The 7075 aluminum alloy is frequently used in aircraft. On parts that require high hardness and strength. Although this material and other aluminum alloy materials have good plasticity, they are inevitably faced with a problem of stress corrosion cracking. Due to the increasing demand for 7075 in various industries, the alloys in this series are highly valued for their strength and corrosion resistance. The stress corrosion function of 7075 alloy is relatively complicated, and there are many conditions for its influence. There is no theoretically uniform conclusion in theory, but a research experiment is often carried out by the process of hydrogen induced fracture.
This process is the relationship between the stress corrosion cracking and the hydrogen embrittlement and the evolution rate of the 7075 aluminum alloy in the bimodal peak by means of the hydrogen permeation method of the cathode.
The basic method is to solid solution through an air furnace, recording 5 different time points as several time peaks at a temperature of 393k. After a series of test procedures, the results of several experiments can be obtained. It can be known from the results of hydrogen fixation that the hydrogen content of the second peak is significantly lower than the first peak. The experimental results of CERT show that the tensile properties of aluminum alloy in air and nacl solution in two peak aging conditions can clearly show that the greater the proportion of air, the greater the sensitivity of aluminum alloy scc. From the experimental results of ssrt, it can be known that in the slow-stretching test of the 7075 aluminum alloy, the strength of the fracture of the aluminum alloy in three effective states will decrease to a certain extent in the case of hydrogen charging.
From these experimental phenomena, it can be concluded that the strength and other properties of the 7075 alloy have a bimodal characteristic. The sensitivity of hydrogen is related to the strain rate. Generally, the higher the rate, the 7075 aluminum alloy will not be embrittled. phenomenon.