1. The trace impurities in the aluminum bronze sleeve, such as oxygen, sulfur, selenium, tellurium, etc., have a small solid solubility in copper, and can form brittle compounds with copper, which have little effect on electrical conductivity, but can reduce processing plasticity. When ordinary aluminum bronze sleeves are heated in a reducing atmosphere containing hydrogen or carbon monoxide, hydrogen or carbon monoxide can easily interact with the cuprous oxide (Cu2O) at the grain boundary to produce high-pressure water vapor or carbon dioxide gas, which can crack the copper.
2. Using optical microscope, scanning electron microscope and energy spectrometer to analyze the leakage failure of aluminum bronze sleeve for refrigerator. The results show that the leakage of the aluminum bronze sleeve is caused by the cracks caused by corrosion, and the chloride ion in the oil glue coated on the surface of the copper pipe is the main factor causing the stress corrosion cracking of the aluminum bronze sleeve.
How to solve the cracking of the aluminum bronze sleeve? Before flaring, the aluminum bronze sleeve is evenly heated with a flame and cooled with water. This process is equivalent to annealing, and then the flaring will not crack.
www.cn-czpufa.com