Study Of Metal - Silicon Carbide Ceramic Matrix Composites

SiC ceramics are based in this paper. Firstly 3vol% stainless steel-SiC ceramic matrix composites confirm the best dosages of additives and coats. Then based on these additives and coats, stainless steel-SiC ceramic matrix composites are composed respectively of lvol%, 5vol% and 7vol% stainless steel particles and SiC; similarly W-SiC ceramic matrix composites are made up respectively of lvol%, 3vol% and 5vol% tungsten particles and SiC; Ti-SiC ceramic matrix composites are made up respectively of lvol%, 3vol%, 5vol%, 7vol%, 9vol%, 11vol%, 13vol% and 15vol% titanium particles and SiC; and Mn-SiC ceramic matrix composites are prepared respectively by lvol%, 3vol%. 5vol%, 7vol%, 9vol% and llvol% manganese particles and SiC.Mechanical properties and thermal conductivity of metal-SiC ceramic matrix composites are studied by universal test machine and TO II apparatus for measuring thermal conductivity. SEM and XRD investigate microstrucrure characteristic. And sintering properties, mechanical properties and influencing factors, toughened mechanisms and thermal conductivity of composites are simultaneously discussed, too. Research results indicate as follows:For 3vol% stainless steel-SiC ceramic matrix composites, 3wt% additives and 18wt% coats make relative density and compactness of composites best. With increase of volume fraction of metals, relative density of composites (except tungsten) improves, too. But relative density will trend to decrease (when stainless steel >5vol%, titanium >11vol%, manganese >7vol%) with superfluous metals.With increase of volume fraction of metals, flexural strength, fracture toughness and thermal conductivity of metal-SiC ceramic matrix composites improve obviously. Relative amplitude in flexural strength is 2.02 times of stainless steel, 1.65 times of tungsten, 2.44 times of titanium and 2.17 times of manganese. Relative amplitude in fracture toughness is 1.54 times of stainless steel, 1.59 times of tungsten, 1.86 times of titanium and 1.84 times of manganese. Composites including 5vol% tungsten, titanium, stainless steel and manganese in thermal conductivity respectively improve 5.92times, 5.78 times, 5.09 times and 2.97 times. But 13vol%Ti is 6.97 times.Synchronously, there are some new phases in composites. For example, there is a mullite in stainless steel-SiC ceramic matrix composites, a WC in W-SiC composites, a TiC in Ti-SiC composites and an Al74Si6Mn20 in Mn-SiC composites. They have good effects on mechanical properties of composites.Combined all kinds of factors, a new theoretical formula of toughened mechanisms is introduced. When experimental values of composites including Mn and Ti are added into it, it is very suit. This theoretical formula is availably applied for these kinds of metal-SiC ceramic matrix composites.