The strength of metal will also be related to the imputity content. Sometimes elements are intentionally added to metals, such as adding nikel to copper or phosphorus to steel. Other times, the presence of impurities, such as inclusions(e.g.,oxides) in copper or solute carbon in steel, may be undesired. In order to rationalize these statements, the effect of each on plastic folw in metals needs to be considered. Substitutional atoms take the place of matrix atoms.Because of the mismatch in atom size between the substitutional atom and the matrix atom, the lattice strain may impede dislocation motion and is convetionally considered to be the source of solid solution strengthening in metals. In general, the strengthening increment varies proportionally with the mismatch in atomic size and properties ( specifically modulus) between the solute and solvent atoms.

impurity 杂质

nikel 镍

phosphorus 磷 

inclusion 夹杂物

plastic folw 塑性流动

mismatch错配  

substitutional置换的

matrix 基体

lattice strain晶格应变 

solid solution strengthening 固溶强化

modulus 模量

solute 溶质  

solvent 溶剂