Squeeze casting

The process has been modified by Li et al [158] to work under vacuum, incorporating the continuous removal of AI2O3 by passing the melt through a Fiberfrax ceramic filter—less oxide will be formed under vacuum. 

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S.W. Lim, Y. Nishida, "Superplasticity of whisker reinforced 2024 aluminium alloy composites fabricated by squeeze casting" Scr. Metall Mater. 32, 1911, 1995... 

Meial Mairix Composites. Silicon carbide particles are contributing to easy-to-cast metal-matrix composites (MMCs). When compared with their non-reinforced counterparts, the SiCp/Al components are more wear resistant, stiffer, and stronger, accompanied by improved thermal stability. Additional advantages include lower density and lower cost. Nearly all prior aluminum MMCs required labor-intensive methods, such as powder metallurgy, diffusion bonding, squeeze casting, or thermal spraying. 

A process known as squeeze casting (solidification of liquid metal under pressure) contributes to producing defect-free eastings with improved metallurgical properties. Sec also Casting. 

Preforms for squeeze-cast composites are comprised of ceramic libers, such as AI Oi and SiOs. which are bound into near net (finally desired dimensions) shapes. 

Preform cracking in squeeze-cast magnesium- based composites Stress and temperature... 

Flat tensile creep specimens were machined from the blocks so that the longitudinal specimen axes were either parallel to the plane containing the majority of the long axes of the fibres for the squeeze-cast composites or parallel to the extrusion direction for powder metallurgy materials. Constant stress tensile creep tests were carried out at temperatures from 423 to 523 K. The applied stresses ranged from 10 to 200 MPa. Creep tests were performed in purified argon in tensile creep testing machines with the nominal stress maintained constant to within 0.1% up to a true strain of about 0.35. Almost all of the specimens were run to final fracture. 

Monolithic and short-fibre reinforced squeeze cast... 

Many metal matrix composites are made by squeeze casting in which the molten metal is infiltrated under pressure into a fiber perform. The applied pressure is sufficient to achieve good interfacial bonding with fibers composed of 7 - or 8-alumina because of the small sizes of the grains leading to large active contact surfaces. 

Although the feasibility of fibrous MMCs is technically demonstrated, the cost of the fibers and of the manufacturing processes, e.g., squeeze casting, is still too high. Thus, particulate reinforcements are presently preferred. 

Figure 16.7 Squeeze casting, (a) insert preform into die cavity (b) meter in a precise quantity of alloy (c) dose die and apply pressure (d) remove ram (e) extract component. Source Reprinted with permission from Matthews FL, Rawlings RD, Composite Materials, CRC Press, Boca Raton, 78-117, 2000. Copyright 2000, CRC Press, Boca Raton, Florida.

Aylor and Moran [45], who conducted polarization experiments on Gr/Al MMCs in seawater, also h5rpothesized that diffiision of carbon into aluminum could lower the integrity of the passive film, rendering it more susceptible to breakdown. Wielage [46] reported that the pitting potentials of various squeeze-cast Gr/Al MMCs were approximately 20 mV more active than that of the pure aluminum matrix material in a chloride solution. Aluminum carbide was found at the Gr fiber-matrix interfaces. Shimizu et al. [37], however, found that pitting potentials of a squeeze-cast, short fiber Gr/6061 Al MMC had pitting potentials similar to that of monolithic 6061 Al in a chloride solution. 

Interph2ise formation of AI4C3 was observed in a Gr/Mg (1 % aluminum) MMC produced by squeeze casting. The AI4C3... 

Modi, O. P., Saxena, M., Prasad, B. K., Yegneswaran, A. H., and Vaidya, M. L., Corrosion Behaviour of Squeeze-Cast Aluminium Alloy—Silicon Carbide Composites, Journal of Materials Science, Vol. 27, 1992, pp. 3897-3902. 

Kiourtsidis, G. and Skolianos, S. M., Corrosion Behavior of Squeeze-Cast Silicon Carbide-2024 Composites in Aerated 3.5 wt.% Sodium Chloride, Materials Science and Engineering A, Vol. 248, 1998, pp. 165-172. 

Squeeze Casting. A hybrid metalforming process, combines casting and forging, applying a high pressure (70 N/m2) as the liquid metal solidifies. The process has been applied to produce metal-matrix composites. 

L.H. Han, X.Y. Nie, H. Hu, Electrochemical behaviour of squeeze cast AJ62 magnesium alloy in salt solution and engine coolant . Mater. Technol. 24 (2009) 170-173. 

Kehoe, F.P. and Chadwick, G.A. (1991) Mechanical and physical properties of squeeze-cast aluminium steel matrix composites containing 5%-30% Saffil. Mater. Sci. Eng. A, 135,209-212. 

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