Interfacial phenomena in wettability of TiC by Al–Mg alloys

Contreras, A.; Bedolla, E.; Pérez, R.

doi:10.1016/j.actamat.2003.10.034

Cited by 89 publications

(44 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…As a consequence, coated powders are an ideal starting point [22]. Further, the identification of additives that improve wetting, accelerate diffusion, or harden the composition are linked to interfacial energy and phase relations [23][24][25]. Beyond additives, research also considers processing factors such as particle size, green density, heating rate, peak temperature, hold duration, and cooling rate.…”

Section: Typical Microstructuresmentioning

confidence: 99%

Review: liquid phase sintering

2009

View full text Add to dashboard Cite

Liquid phase sintering (LPS) is a process for forming high performance, multiple-phase components from powders. It involves sintering under conditions where solid grains coexist with a wetting liquid. Many variants of LPS are applied to a wide range of engineering materials. Example applications for this technology are found in automobile engine connecting rods and high-speed metal cutting inserts. Scientific advances in understanding LPS began in the 1950s. The resulting quantitative process models are now embedded in computer simulations to enable predictions of the sintered component dimensions, microstructure, and properties. However, there are remaining areas in need of research attention. This LPS review, based on over 2,500 publications, outlines what happens when mixed powders are heated to the LPS temperature, with a focus on the densification and microstructure evolution events.

show abstract

Section: Typical Microstructuresmentioning

confidence: 99%

Review: liquid phase sintering

2009

View full text Add to dashboard Cite

show abstract

“…It has been established theoretically and experimentally in the literature that the formation of oxides in Al-Mg alloys is dependent on the Mg content in the alloy and the melting conditions [25][26][27][28][29]. However, there is very limited information on the microstructural features of the oxides formed in liquid Al-Mg alloys due to the associated experimental difficulties [27].…”

Section: The Nature Of Oxides In Molten Al-mg Alloysmentioning

confidence: 99%

Mechanisms of enhanced heterogeneous nucleation during solidification in binary Al–Mg alloys

Li¹,

Wang²,

Fan³

2012

Acta Materialia

184

120

View full text Add to dashboard Cite

This paper investigates the mechanisms involved in the grain refinement of Al-Mg alloys through varying the Mg content and applying intensive melt shearing. It was found that the oxide formed in Al-Mg alloys under normal melting conditions is MgAl 2 O 4 , which displays an equiaxed and faceted morphology with {111} planes exposed as its natural surfaces. Depending on the Mg content, MgAl 2 O 4 particles exist either as oxide films in dilute Al-Mg alloys (Mg<1wt.%) or naturally dispersed discrete particles in more concentrated Al-Mg alloys (Mg>1wt.%). Such MgAl 2 O 4 particles can act as potent sites for nucleation of α-Al grains, which is evidenced by the well-defined cube-on-cube orientation relationship between MgAl 2 O 4 and α-Al. Enhanced heterogeneous nucleation in Al-Mg alloys can be attributed to the high potency of MgAl 2 O 4 particles with a lattice misfit of 1.4% and the increased number density of MgAl 2 O 4 particles due to either natural dispersion by the increased Mg content or forced dispersion through intensive melt shearing. It was also found that intensive melt shearing leads to significant grain refinement of dilute Al-Mg alloys by effective dispersion of the MgAl 2 O 4 particles entrapped in oxide films, but it has marginal effect on the grain refinement of concentrated Al-Mg alloys, where MgAl 2 O 4 particles have been naturally dispersed into individual particles by the increased Mg content.

show abstract

“…However, in previous works of wetting of TiC by Al and Al-Mg alloys the Al 4 C 3 phase was observed. [20,21] These results suggest that the absence of reaction products in the present composites is chiefly due to kinetic factors.…”

mentioning

confidence: 58%

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

Contreras¹,

Albiter²,

Bedolla³

et al. 2004

Adv Eng Mater

View full text Add to dashboard Cite

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...

show abstract

Interfacial phenomena in wettability of TiC by Al–Mg alloys

Cited by 89 publications

References 22 publications

Review: liquid phase sintering

Review: liquid phase sintering

Mechanisms of enhanced heterogeneous nucleation during solidification in binary Al–Mg alloys

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

Contact Info

Product

Resources

About