Modeling of Sonotrode System of Ultrasonic Consolidation With Transfer Matrix Method

To establish an efficient model for sonotrode system, a key part that continuously applies ultrasonic oscillation on metal foils to form solid state bond in ultrasonic consolidation equipment, this research presents modeling methods for sonotrode system. After an introduction to the construction of sonotrode system along with its operating principle, the transfer matrix method was adopted to build the model for the system consisting two ultrasonic transducers and one sonotrode. Simulation results of transfer matrix model were compared to that of finite element method. A prototype was fabricated and tested. A comparison of the resonance frequencies calculated by two modeling methods to the experimental result showed that the difference between transfer matrix model and prototype is 6.96% while the difference between finite element model and prototype is 9.26%. The proposed transfer matrix method is an efficient way to simulate dynamic performances for sonotrode system, which provide a better foundation for further optimization.

FIBROUS COMPOSITE MATERIALS WITH A METAL MATRIX (review)

The article provides an overview of the literature in the field of composite materials (CM) based on metal matrices reinforced with carbon fibers. The main structural, physical and mechanical properties and morphology of such CMS are briefly described. The structure and properties of new CMS from multilayer metal-intermetallic multilayer laminates reinforced with carbon and ceramic fibers are also presented. Application of the method of ultrasonic consolidation for the manufacture of multilayer fibrous CMs based on metal-intermetallic laminates provides high adhesion of fibers with an intermetallic layer.

An investigation of the mechanical properties and bonding mechanism of Ti/Al-laminated composites fabricated by ultrasonic consolidation

Foils such as 1100 aluminum and TC4 titanium were used as matrix materials for ultrasonic consolidation test of dissimilar metal materials, and the samples of Ti/Al-laminated composites were prepared. The effect of amplitude and static pressure on the interfacial bonding strength of Ti/Al foil was studied by adhesion test. The mechanical properties of Ti/Al-laminated composites were tested by electronic universal testing machine. The microstructure of Ti/Al foil interface was observed by transmission electron microscope. The results show that ultrasonic consolidation can achieve a good bonding interface of Ti/Al foil, and the bonding strength of the interface increases first and then decreases with the increase of static pressure, and increases monotonously with the increase of amplitude. The optimum adhesion strength is 58.08 N cm−1. The high temperature deformation constitutive model of Ti/Al-laminated composites is established and verified. The Ti/Al interface has metallurgical bonding, and the inner microstructure of Ti/Al matrix is obviously refined. The surface of titanium foil has formed nanocrystalline.

High-speed consolidation and repair of carbon fiber/epoxy laminates through ultrasonic vibrations: A feasibility study

Ultrasonic welding is a common fusion bonding technique to join unreinforced and reinforced thermoplastics. It is expected that applying ultrasonic vibrations to thermoset prepregs can produce heat generation to promote resin flow and consolidation. This paper discusses the feasibility of using ultrasonic vibrations as a high-speed repair technique for carbon fiber/epoxy prepregs to replace the traditional vacuum-bagging scarf setup. Three material types were investigated: out-of-autoclave unidirectional and plain weave prepregs (Cycom® 5320) and a general purpose twill weave prepreg (AS4/Newport 301). Two welding modes were considered: time and travel (vibrations stop once the desired vertical displacement is reached). For each mode, vibration time, travel, force, and amplitude were investigated. Cross-sectional analysis showed that void content equal to or below the vacuum-bagged samples could be achieved with ultrasonic consolidation to meet aerospace standards (≤2%). The following ultrasonic parameters were recommended to preserve prepreg tows integrity and minimize void content: vibration time below 1.0 s, travel between 12.5% and 50% of sample's initial thickness, force equal to or below 100 N, and amplitude below 41.3 μm. Temperature values recorded during the ultrasonic process reached the manufacturer's cure temperature range (120℃ to 180℃), with a predicted maximum degree of cure of 0.24. Interlaminar shear strength values were comparable for ultrasonically consolidated and vacuum-bagged samples. Soft and hard repair patches were applied to open-hole tensile coupons, with up to 50% strength recovery for both repair methods. Overall, ultrasonic consolidation has potential as a time- and cost-efficient repair method for thermoset prepregs.