Design and analysis of long-stepped horn for ultrasonic-assisted sintering

ABSTRACT

In the recent past, ultrasonic vibrations have been incorporated in sintering to improve the performance of the product and process. The ultrasonic vibration accelerates the diffusion process in the solid-state fabrications. The ultrasonic system consists of ultrasonic generator, transducer and horn. The design of ultrasonic horn is a challenge for ultrasonic-assisted sintering (UAS) due to the involvement of high temperature. In this study, a long step horn was designed as per the sintering furnace requirement. The horn was designed with multi-nodes and anti-nodes working at 20 kHz frequency and having approximate 20 µm vibration at the horn end. The methodology was used to analyse step horn design with the help of modal and harmonic analysis to maximise the amplitude at the horn end. Additionally, modal analysis at elevated temperatures was carried out by coupling thermal dependent properties, and it was observed that the natural frequency and the harmonic amplitude decreased. The designed horn has been used to sinter bronze spherical powder at 700 and 800 ${\hspace{0.17em}}^{\circ }C$ sintering temperature for 1 hr of soaking time to study the effect of ultrasonic vibration on the densification behaviour. The results showed better homogeneity and density as compared to conventional sintering process.

KEYWORDS:

• Ultrasonic sintering
• harmonic analysis
• thermal modal analysis
• long-stepped horn
• powder densification

Disclosure statement

No potential conflict of interest was reported by the authors.