smeltinfiltratie

Smeltinfiltratie is a metallurgical term describing the process by which molten metal or slag penetrates into a porous or permeable solid during smelting, casting, or related operations. The phenomenon can lead to the formation of metal-filled pores, metallurgical composites, or, in some cases, unwanted bonding between the melt and the substrate.

The process is driven by capillary action and gravity and is strongly influenced by melt viscosity, surface tension, temperature, and wetting behavior. Materials with interconnected porosity, such as ceramic foams, porous refractories, or graphite and ceramic linings, are susceptible when the melt wets their surfaces. The rate and depth of infiltration depend on pore size distribution, permeability, contact angle, and the duration of contact between melt and substrate.

Applications include the production of metal-matrix composites through infiltration of liquid metal into ceramic preforms, and the use of infiltration in forming or strengthening porous molds. Conversely, uncontrolled infiltration can degrade refractory linings, cause exothermic or chemical reactions, or create metal residues that are difficult to remove. In process control, coatings, barrier layers, or non-wetting inserts are used to limit infiltration where it is undesirable.

Characterization of infiltration depth and distribution is typically done by microscopy, tomography, or sectional analysis, with results feeding adjustments to temperature, soak time, and melt composition. The term is most common in Dutch-language technical literature and is applied to both beneficial and detrimental infiltration phenomena depending on context. See also capillary action; metal-matrix composites; porous ceramics; refractory materials.