Investigate and study parameters for successful hot embossing of metal micro devices for new applications.
Lean, Hui Yuan.
Date of Issue2009
School of Mechanical and Aerospace Engineering
The main focus of the project involved the study of different hot embossing parameters that affect the replication quality on metal substrates. Initially, binder system made up of Paraffin Wax (25-weight %), Ethylene Vinyl Acetate-460 (35-weight %) and Low Density Polyethylene (40-weight %) were mixed with water atomized 316L stainless steel powder to form a homogeneous feedstock. The feedstock in turn consists of 92-weight % of 316 L stainless steel powder and 8-weight % of binder system. Subsequently, the feedstock was shaped into pellets and used for metal injection moulding to produce the metal substrates. Before proceeding with the hot embossing experiment, the thermal properties of the feedstock were determined by the use of Thermogravimetric Analyzer (TGA) and Differential Scanning Calorimeter (DSC). The results obtained were tused as a guideline to allocate values to the various temperatures like embossing temperature and demolding temperature. Next, a screening experiment (DOE) was done to examine which hot embossing parameters have significant effect on the replication quality. Due to the time limitation, only temperature, pressure and time for embossing and re-embossing were examined. In addition, instead of measuring the depth replicated, the width of the u and y channels and the radius of the reservoir were measured. Consequently, the significant parameters were treated as variable parameters, while the insignificant parameters were given a fixed value. Optimization experiments were done for each of the significant parameters to obtain the optimum values that give good replication quality.
Final Year Project (FYP)
Nanyang Technological University