API 571 Certification (Corrosion & Materials) Practice Test

Which materials are known to be affected by liquid metal embrittlement, except as noted?

1. High-strength steels

2. Copper and aluminum alloys

3. Titanium alloys

4. All of the above

The correct answer is: All of the above

Liquid metal embrittlement is a phenomenon where certain metals become brittle and lose their ductility when they come into contact with liquid metals, particularly at elevated temperatures. High-strength steels, copper and aluminum alloys, and titanium alloys are all known to be susceptible to this form of embrittlement under certain conditions. High-strength steels are particularly vulnerable because the presence of liquid metals can lead to the diffusion of liquid into the grain boundaries, which enhances the likelihood of brittle fracture under tensile stress. This is critical in applications where the mechanical integrity of steel components is essential. Copper and aluminum alloys can also suffer from the effects of liquid metal embrittlement, especially when exposed to molten zinc or lead. The alloying elements and the solid solution can be disrupted, leading to deterioration in mechanical properties. Titanium alloys can experience liquid metal embrittlement due to their high reactivity and the narrow temperature range in which they are susceptible. Specifically, interactions with elements like mercury can significantly affect the microstructure and integrity of titanium alloys. The option stating "all of the above" accurately encompasses these materials, highlighting the broad impact of liquid metal embrittlement across various high-performance alloys in different applications. Therefore, recognizing the susceptibility of these materials is crucial for engineers and material scientists