Incongruent Melting of Solders
Incongruent melting of solders: The melting of solder alloys over a wide temperature range, where both solid and liquid phases coexist. This can lead to segregation tendencies and uneven deformation.
Physicochemical Mechanism of Action
In incongruent melting of solders, there is a wide temperature range between the solidus and liquidus temperatures. In this range, both solid and liquid phases coexist. The different phases can move and mix with each other, leading to segregation tendencies.
Metallurgical Relevance & Risks in Welding
Incongruent melting can lead to uneven deformation of the solders, as the solid phase is less fluid and moves slower. This can result in stress buildup and cracks in the solders. Additionally, segregation of metals and alloys can lead to altered chemical composition, which can impair the properties of the weld.
Workshop Practice & Action Guidelines
To minimize incongruent melting, solders with low stress and uniform deformation should be used. The melting temperature should be set so that the melting range is kept as short as possible. This can be achieved by selecting the right welding process and proper solder manufacturing.