How does the brazing process affect the thermal properties of the metals involved?

The brazing process can significantly alter the thermal properties of the metals involved, which is why the correct choice highlights its ability to affect both thermal conductivity and expansion. When metals are joined through brazing, the heat from the brazing process can cause changes to the microstructure of the base materials as well as the filler material used in the joint.

During brazing, the elevated temperatures can result in changes such as grain growth or phase transformations within the metals, which can directly impact their thermal conductivity. For instance, some metals may exhibit a higher thermal conductivity post-brazing, while others may show reduced conductivity due to altered microstructure. Additionally, the differences in thermal expansion coefficients between the base materials and the filler metal can lead to stresses as they expand and contract at different rates with temperature changes. This interaction is crucial for maintaining the integrity and functionality of the brazed joint in applications subjected to thermal cycles.

Understanding these alterations is vital, particularly in applications where thermal efficiency and stability are essential. Thus, the process does indeed influence thermal properties, making the choice that indicates alteration in thermal conductivity and expansion accurate and significant in the context of brazing.