koostalitlus

Koostalitlus is the formation of a material that consists of two or more distinct chemical phases that are intimately mixed and share boundaries, creating a coherent or semi-coherent texture. The term is used in geology, mineralogy and materials science to describe intergrowths where phases are closely connected rather than simply juxtaposed.

In geology, koostalitlus can arise during crystallization from a multicomponent melt, producing eutectic or two-phase intergrowth textures, or by exsolution, where a solid solution separates into two phases upon cooling or pressure change. Metamorphic and hydrothermal processes can also promote the development of intergrowth textures through replacement and rearrangement of minerals. These textures record information about temperature, pressure, and chemical conditions during rock formation and alteration.

In materials science and metallurgy, the concept describes alloys or ceramic composites in which different phases form fine intergrowths or lamellae with interfaces that influence mechanical properties such as strength, hardness and toughness. The microstructure can range from evenly distributed fine intergrowths to coarser, oriented lamellae, depending on cooling rates, composition and diffusion dynamics.

Analytical approaches to identify and characterize koostalitlus include optical petrography, scanning electron microscopy with energy-dispersive X-ray spectroscopy, electron probe microanalysis and X-ray diffraction. By studying these textures, scientists infer formation histories, thermal regimes and the evolution of the material.