Ultrasonic dissolution of solid Al in liquid Sn during soldering: Modeling and equation, trend prediction,...

Area of Science:

• Materials Science
• Metallurgy
• Surface Engineering

Background:

• Soldering ceramics/metals with inexpensive, inactive solders is desirable but hindered by unquantified base metal dissolution.
• Understanding aluminum (Al) dissolution in liquid tin (Sn) is critical for optimizing joining processes.

Purpose of the Study:

• To investigate and quantify the dissolution behavior of solid Al in liquid Sn, both with and without ultrasonic irradiation.
• To establish a physical model and derive equations for Al dissolution kinetics.
• To elucidate the mechanism by which ultrasound affects Al dissolution.

Main Methods:

• Experimental dissolution of solid Al in liquid Sn at various temperatures and Sn layer thicknesses.
• Application of the Nernst-Brunner principle to model dissolution kinetics.
• Analysis of bubble dynamics to understand ultrasonic effects.

Main Results:

• A physical model and relationship equation for Al concentration (Ca) and soldering time were established.
• Ultrasound significantly increased the dissolution rate constant (K) by 5.8 times and maximum Al concentration (Ca) by 4.5 times at 250°C.
• Activation energy for dissolution was reduced by 41% under ultrasound, indicating enhanced dissolution kinetics.

Conclusions:

• Ultrasound dramatically accelerates the dissolution of Al in Sn, with reduced sensitivity to temperature and Sn layer thickness compared to non-ultrasonic conditions.
• The findings provide a quantitative understanding and a mechanistic explanation for ultrasonically enhanced dissolution.
• This research offers valuable guidelines for designing effective ceramic/metal soldering processes using inactive solders.