Numerical investigation of ultrasonic cavitation in stir cast aluminium matrix melt composites

• Main Authors: S.V., Jyothish, Natarajan, Ganesh, S., Kanmani Subbu
• Format: Conference Proceeding
• Language: English
• Subjects: Acoustic properties; Acoustic streaming; Acoustics; Aerospace industry; Aluminum base alloys; Aluminum matrix composites; Cavitation; Containers; Corrosion fatigue; Corrosion resistance; Fatigue strength; Mass production; Mechanical properties; Microprocessors; Parameters; Reinforcement; Strength to weight ratio; Ultrasonic vibration; Weight reduction; Wettability
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0134309

Aluminium matrix composites (AMCs) have found widespread applications in automobile, aerospace and marine industries because of their attractive properties. These include good strength to weight ratio, better corrosion and fatigue resistance. Stir casting has been identified as the most suitable method to fabricate AMCs because it provides good matrix-reinforcement bonding while also being a cost-effective process for mass production. However, this process suffers from drawbacks that include cast porosity, less wettability and agglomeration of reinforcement particles. A means to overcome these disadvantages is the use of acoustic cavitation using ultrasonic vibrations which can scatter the agglomerated particles and creates a uniform distribution of particles through acoustic streaming. Since the effect of ultrasonic cavitation is extremely localized, it is often combined with stir casting method to leverage the advantages of both approaches while negating their respective demerits. This hybrid approach known as Ultrasonic Assisted Stir Casting can be used to fabricate AMCs with better mechanical properties. The regions of cavitation as well as acoustic streaming in this process are strongly influenced by parameters such as power, wave frequency and container geometry which directly impact the performance characteristics of the process. In this work, we numerically investigate the influence of acoustic parameters and geometry of the processor container on cavitation regions and acoustic streaming. Simulation results showed that the cavitation region is concentrated near to the sonotrode and the acoustic streaming results in a circulating flow within the processor container.The analysis of cavitation zones and streaming patterns in these preliminary studies without reinforcement particles is expected to provide insights to optimize the acoustic parameters for uniform distribution of particles.