Effect Of Reinforcment Dispersivity On PRMMCs’s Dimensional Stability

Increasingly high degree of precision of modern industry have become increasinglydemanding dimensional stability of the material traditional alloys can not meet therequirements of particle reinforced metal matrix composites researchers most concernedabout the preferred material because of its excellent dimensional stabilityhas beenapplied successfully. But the stability of the design study the material stability design ofquantitative, semi-quantitative studies have not reported. Therefore, the design study onthe dimensional stability of the metal matrix composites have important theoreticalsignificance and value of the works.The metal matrix composites, the major semi-quantitative control elements is toenhance the size and volume fraction of phase, this paper presents the concept ofdispersivity to a unified description, try to solve the basic theory of material design.SEM, TEM, and cellular automata simulation, micro-yield strength testing and dynamicdimensional stability testing of a variety of research methods, analysis of thedispersivity on the microstructure of, and explore the enhanced phase dispersivity andparticle reinforced metal matrix composite the relationship between the materialdimensional stability and the establishment of the following relationship:DF_s=[DF_s0 DF_s1 DF_s2 DF_s3]Dispersivity expression vector form, and to consider the enhanced phase particlesize distribution, component, said its diffusion in various dimensions. Enhanced phasevolume fraction greater the smaller the size, the greater dispersivity of each component.This article select1060industrial pure Al as matrix, selection of5m、10m20m、30m and63m in five different sizes of SiC particles were prepared by thereinforcing phase, respectively15%,25%,35%,45%of the twenty kinds of SiC/Alcomposites, and after annealing350C for1h,furnace cooling.By SEM, TEM observation shows that the composite interface combined with agood, clean, free of impurities and precipitated phase; enhance the uniformity of thedistribution phase of the dispersion degree are better, the composite matrix will appearin the entanglement state dislocation organizations and The subgrain organization.Cellular automata simulation shows that the enhanced phase diffusion when the matrixgrain size is also smaller.The enhanced phase of the dispersion of the composite micro-yield strength, yieldstrength and dynamic dimension stability of. Micro-yield strength and yield strength isincreased with the increase of for dispersivity dimensional component, dynamic dimensional stability with the increase of dispersion degree of three-dimensionalcomponent to improve, lower with two-dimensional component of the increase.According to the results of this experiment, analysis of the enhanced phase of thedispersion degree of dimensional stability of the law, micro plastic dependent resistanceof the substance is to impede dislocation motion, dynamic dimensional stability in realterms, reduce the internal stress relaxation. Establish a theoretical model and calculatethe results and the actual fitting better. This should be selected high volume fraction,and small size particles as the reinforcing phase, to make it at all levels have a higherdegree of dispersion. Therefore, under our experimental conditions, diffusion is[6.9×10¹⁵1.6×10⁷8.1×10⁵4.5×10^-1]showed excellent dimensional stability, andcorresponding dispersivity composite design parameters for SiC,the volume of45%sand the size of5m of the composite stability The best micro-plastic deformationresistance166.2Mpa the thermocycling residual deformation value of3.91×10^-6.