Speaker
Description
CMCs (ceramic matrix composites) provide interesting properties when they are employed in applications that must withstand harsh environments. These materials overcome the limit of utilization due to the brittleness of ceramic materials and they have been experiencing a growing popularity in aerospace and energy fields.
CMCs often need to be integrated together with themselves or dissimilar materials, but this can be difficult due to joining issues. A viable approach to improve the joint strength is the surface modification of the materials to be joined in order to obtain a surface structure that promotes the interlocking mechanism between the treated surface and the joining material.
The experimental work presented hereby is focused on the assessment of the feasibility of the selective etching provided by the atmospheric-pressure plasma jet (APPJ) as a solution to improve the joint strength for carbon fiber-reinforced carbon (C/C) and carbon fiber-reinforced silicon carbide (C/SiC) materials. The preliminary part of the experimental activity suggested that the APPJ-induced surface modification resulted in a superficial selective removal of fibers. Furthermore, it pointed out that the treatment can provide a significant increase in the surface area, which is beneficial to improve the effectiveness of joining. Because of the increment of the available joining area and of the induced surface morphology an enhancing of the interlocking mechanism is expected in joints.
At this stage of the research, this modification process seems to be not detrimental for the thermomechanical properties of the whole CMCs.
The assessment on the effectiveness of the surface treatment as a joint strength enhancer has been carried out by collecting and comparing results from wettability test and joint strength tests on the APPJ-etched CMCs and on the untreated CMCs. First findings are presented
| Speaker Country | Italy |
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