2013

Hybrid adhesive joining techniques are often used in many industrial sectors to design lightweight structures. A hybrid adhesive joint results from the combination of adhesive bonding with other traditional joining methods such as welding and mechanical fastening, with the aim of combining the advantages of the different techniques and overcoming their drawbacks. This study focuses on the interference fitted/adhesive bonded joining technique. In this application, two cylindrical components are coupled together by inserting one into the other, after having placed an adhesive between them.

Electrodeposition is well-known as a versatile and economical processing technique to produce metal coatings on conductive substrates. Recently, it has been gaining increasing interest also for the production of tailored composite coatings, containing for instance floropolymers or silicon carbide. A more novel approach concerns the use of carbon nanotubes or even graphene, in the form of graphite nano-platelets.

A processing method common to composite ceramics with very different ZrB2/SiC ratios was developed in order to exploit ZrB2–SiC laminates comprising alternate layers with different compositions for thermal protection systems of re-entry vehicles. Ceramic laminates were made using SiC, ZrB2 and composites with a SiC/ZrB2 ratio ranging from 100 vol.-%SiC to 100 vol.-%ZrB2. The preparation was performed by tape casting of a slurry, layer stacking, debinding and pressureless sintering.

Phase transition temperatures of γ-TiAl alloys were successfully identified by Thermo Mechanical Analysis. The derivative curve of the displacement as a function of temperature exhibits well defined peaks at the temperatures 1100 ≤ Teu ≤ 1200 °C and 1250 ≤ Tα ≤ 1350 °C which correspond to the phase transformations (α2 + γ) ↔ α and (α + γ) ↔ α respectively. The well-known effects of Al and Nb content on transition temperatures were studied for validation.

n the present work, milled carbon fibre with high mechanical properties was used to reinforce silicon carbide, and Csf/SiC multilayer composites were prepared by tape casting and pressureless sintering. The milled C fibres were firstly dispersed in solvents with the aid of dispersant (Triton X-100) and then mixed with SiC slurry to make green Csf/SiC tapes to limit fibre breakage.

Direct metal laser sintering (DMLS) is an additive manufacturing (AM) technology for the fabrication of near netshaped parts directly from computer-aided design (CAD) data by melting together different layers with the help of a laser source. Its application for manufacturing three- dimensional objects represents one of the promising directions to solve challenging industrial problems. This approach permits to extend significantly the freedom of design and manufacture by allowing, for example, to create an object with desired shape and internal structure in a single fabrication step.