Processing and Characterization of Al‐Cu and Al‐Mg Base Composites Reinforced with TiC

Abstract

elements will contain diamond cutting plates since preliminary studies carried out at MTU Aero Engines proofed that this material shows practically no attrition when cutting the fibers.Laser cutting does not lead to a proper cutting surface. This process is therefore not suitable for further application. Together with laser cutting a so called ªonion-structureº was observed on the pyrolithic carbon coating of SiC fibers, which leads additionally to a fiber destruction at the interface SiC to Titanium coating. Two possible explanations can be given for this effect. Either it is due to a reaction between the Titanium 6±4 and the pyrolithic graphite layer or due to the destruction of bonds between the atomic layers of graphite as a result of heat influence.Conclusions: This paper described different cutting methods for SiC fibers (bending, scissors cutting and laser cutting) and evaluated the results. The laser cutting method is not suitable due to the change in fiber morphology at the cut surfaces and the destruction of the pyrolithic graphite interlayer. Scissors cutting of fibers is problematic as well. The two scissor blades penetrate the fiber and generate a complex stress field, which may lead to chip fractures with undesirable particle contamination. According to the evaluated results cutting by bending is the best method. The fracture is plane and perpendicular to the fiber axis, producing a smooth fracture surface at a predictable location without particles. ExperimentalUncoated and coated SiC fibers were cut by a CO 2 laser. The laser RS500/ 700 was supplied by ROFIN-SINAR Hamburg, Germany.For cutting two plates on which the fibers were fixed with adhesive tapes were prepared. These plates were separated by a distance of 2,5 cm. At the point equidistant from both plates, the laser cut into the fibers.The laser used had a focal distance of 1000 lm. Since the diameter of the fibers is about 140 lm and due to the fact that the laser lens focus could be moved only in steps of 100 lm, a distance of the fiber surface to the laser lens of 900 lm was selected. This way the focus of the laser was about 40 lm within the fiber itself. Laser power was increased in steps of 10 W starting at 0 W and ending at 260 W or 290 W for the coated and uncoated SiC fibers respectively.All of the presented electron microscope scans were obtained by means of an SEM CamScan S2, Cambridge, UK equipped with an energy dispersive microanalyser (EDX, Edwin M-series, Röntec, Berlin, Germany).The cutting depths of the coated and uncoated SiC fibers were determined by means of MS Picture Publisher .Metal matrix composites (MMCs) reinforced with ceramic particles offer high strength and high values of the elastic modulus as well as good high-temperature properties compared to the corresponding monolithic materials used as the matrix. [1] The nature of the technique used in the fabrication of MMCs has a significant effect on the overall properties of the product. In the case of the liquid-metal processing of composites, a major difficulty fo...

Wetting of TiC by Al–Cu alloys and interfacial characterization

“…They obtained contact angles around 126 • , 115 • , and 105 • for 1100, 1130, and 1170 • C. More recently, Zarrinfar et al [14] reported poor wetting between molten copper and TiC which makes difficult to produce copper based ceramics composites. However, in previous work was reported the fabrication of Al-Cu alloys/TiC composites processed by the pressureless infiltration technique at temperatures of 900 and 1000 • C [17]. The poor wettability is attributed to the stable electron configuration of copper which has a full "3d" orbital.…”

Fabrication of Nanosized Al<SUB>2</SUB>O<SUB>3</SUB> Coated Reinforcing Particle Using Electrostatic Force

“…In addition, in the EDS results, the polygonal and pellicle shapes shown in Figures 4 and 5(a) consist of the Ti and Al atoms, respectively. 12 It is verified that the Al precursor coated on the TiC particle becomes the amorphous Al 2 O 3 after heat treatment at 500 C. …”

Electrochemical Characterization of the Aluminum–Copper Composite Material Reinforced with Titanium Carbide Immersed in Seawater

“…These MMCs have been displacing to the commercial steels, mainly when specifi c properties are needed [ 1 ]. The greatest diffi culty in the composite manufacture at liquid state is the wettability of the ceramic phase on the liquid metals [ 2 ]. According to this fact, it is important to improve the wettability in order to get a good junction between the metallic matrix and the ceramic [ 3 ].…”