Document Type : Original Article
Author
Department of Chemical Engineering, Calgary University, Canada
Abstract
Percolation is a process similar to sintering with a liquid phase, except that here the solid phase is first formed in a porous molded body, and the solid metal phase is formed from the outside during sintering and is allowed to permeate the porous system. Additional shrinkage can be prevented by liquid phase sintering, which results in dimensional stability of the product except for one percent growth, which is due to a thin surface layer of liquid metal formed on the part. This method is used for systems that have two or more components and their melting temperatures are very different. Excluding the hot compaction method, percolation is the only powder processing method that can produce a perfect density close to the lattice shape. All other densification processes require the material to shrink and thus destroy the correct shape and dimensions. With machining, pressure densification or powder injection into the mold, seletonization is formed earlier than percolation, complexity in the design of parts such as cuts, internal angles and multiple surfaces that can be released to size in high density parts. which are produced by extrusion or hot pressing are not possible. Another unique feature of percolation is that under suitable conditions for segment angles and limited solubility between low-melt and high-melt phase systems, fully entangled continuous networks can be obtained. This is an important issue for manufacturing products that must have a combination of high thermal and electrical conductivity with an acceptable level of strength and resistance to erosion.
Keywords
Main Subjects
)