Fibre laser joining of highly dissimilar materials: Commercially pure Ti and PET hybrid joint for medical device applications

Abstract

Laser transmission joining (LTJ) is growing in importance, and has the potential to become a niche technique for the fabrication of hybrid plastic-metal joints for medical device applications. The possibility of directly joining plastics to metals by LTJ has been demonstrated by a number of recent studies. However, a reliable and quantitative method for defining the contact area between the plastic and metal, facilitating calculation of the mechanical shear stress of the hybrid joints, is still lacking. A new method, based on image analysis using ImageJ, is proposed here to quantify the contact area at the joint interface. The effect of discolouration on the mechanical performance of the hybrid joints is also reported for the first time. Biocompatible polyethylene terephthalate (PET) and commercially pure titanium (Ti) were selected as materials for laser joining using a 200 W CW fibre laser system. The effect of laser power, scanning speed and stand-off distance between the nozzle tip and top surface of the plastic were studied and analysed by Taguchi L9 orthogonal array and ANOVA respectively. The surface morphology, structure and elemental composition on the PET and Ti surfaces after shearing/peeling apart were characterized by SEM, EDX, XRD and XPS.

Porosity Elimination in Modified Direct Laser Joining of Ti6Al4V and Thermoplastics Composites

“…The fracture strength of the produced joints monotonically increases with increasing structure density, and reaches up to around 41.5 MPa as the structure density increases to 75%. This fracture strength is much higher than the reported joints produced between cyclic olefin polymer (COP)/PA6.6-GF35 and steel (<22 MPa) [22,23], PA66-GF30/Acrylonitrile butadiene styrene (ABS) and aluminum (<22 MPa) [9], PET and titanium (<20 MPa) [14,24] by the laser joining process.…”

Fibre laser nitriding of titanium and its alloy in open atmosphere for orthopaedic implant applications: Investigations on surface quality, microstructure and tribological properties

“…Finally, the discoloured areas (or blue-coloured areas) in the nitride surfaces were measured using the Colour Threshold function in ImageJ (see example in Figure 2(b) for the image after measurement). Detailed procedures for the ImageJ analysis were given in the authors' previous study [23]. The concentration of surface discoloration (i.e.…”

Dry Sliding Wear and Surface Morphological Examination of an Aluminium Matrix Composite Reinforced With Palm Kernel Shell

“…This automatic image analysing software is capable of defining and counting object in the picture, analysing their surface, length, boundaries, moments, quantifying of grains and measurement of grain sizes, the volume fraction of phase and depositing the results of analyses to spreadsheet data files [18]. The following procedures with detailed description given in [22,23,37,38] were applied in conducting the ImageJ analysis: firstly, the surface morphology of the composites and the unreinforced aluminium alloy samples was captured by an optical microscope and exported as a high-resolution micrograph. Then the high-resolution micrograph was imported in the ImageJ software for image analysis.…”