Application of ultrasonic excitation to metal forming processes M. Rosochowska Manufacturing Engineering Research Group

Overview Objective Results Approaches Findings Future work

Objective Define the constraints to the application of ultrasonic to metal deformation

Approaches Definition of processes: Experimental Analysis Finite Element Analysis Process simulation Equipment design - FE methodology Parameters: Indentation Heading Wire flattening Back extrusion Amplitude of vibrations Deformation velocity Materials

IndentationHeading Wire flattening Back extrusion

The Tool

FE results Punch holder suspension Vibration mode, Frequency 20kHz

FE analysis of threaded joint between punch and tool holder a) excitationa) tightening Stresses induced by:

FE results Simulation of wire- flattening Stress distributionTool load V=150mm/s

Experimental results Indentation Steel Aluminium

Experimental results Heading of Aluminium h H DoDo D

Experimental results Wire-flattening Copper wire mm  h d o Cu Al Al-G r =

Experimental results Back extrusion Steel v=0.25mm/s, A=7.2  m1 - v=1mm/s, A= mm/s, A=4.3  m 2 - v=10mm/s, A=2.8  m mm/s, A=4.6  m 3 - v=5mm/s, A=2.8  m 6 - 1mm/s, A=8.3  m Aluminium

Findings Forging force - inversely proportional to excitation amplitude and directly proportional to deformation velocity Excitation applicable to slow deformation-rate processes Industrially-significant forming force reduction in wire flattening and back extrusion

Findings High-strength work-materials require excessive amounts of energy to excite tools. Excitation applicable to processes in which deformation field in the work-material remains in steady-state Excitation amplitude limited by the permissible stresses and tolerable thermal changes in tools

Findings Application limited to small components The process is expensive because tool design is complex and energy consumption relatively large. Application limited to low-strength work-materials

Proposed future work Evaluate prospects of forming miniature components Evaluate prospects of using environmentally- friendly lubricants Evaluate machine design requirements for utilisation of tool excitation