Design of experiment approach for sintering study of nanocrystalline SiC fabricated using plasma pressure compaction

Plasma pressure compaction (P2C) is a novel sintering technique that enables the consolidation of silicon carbide with a nanoscale microstructure at a relatively low temperature. To achieve a high final density with optimized mechanical properties, the effects of various sintering factors pertaining to the temperature-time profile and pressure were characterized. This paper reports a design of experiment approach used to optimize the processing for a 100 nm SiC powder focused on four sintering factors: temperature, time, pressure, and heating rate. Response variables included the density and mechanical properties. A L9 orthogonal array approach that includes the signal-to-noise (S/N) ratio and analysis of variance (ANOVA) was employed to optimize the processing factors. All of the sintering factors have significant effect on the density and mechanical properties. A final density of 98.1% was achieved with a temperature of 1600?C, hold time of 30 min, pressure of 50 MPa, and heating rate of 100?C/min. The hardness reached 18.4 GPa with a fracture toughness of 4.6 MPa?m, and these are comparable to reports from prior studies using higher consolidation temperatures. Kompresija plazma pritiskom (P2C) je nova tehnika sinterovanja koja omogucava zgusnjavanje silikon karbida sa nano mikrostrukturom na relativno niskoj temperaturi. Karakterisani su uticaji razlicitih faktora sinterovanja u odnosu na profil temperatura-vreme i pritisak u cilju dobijanja velike finalne gustine sa optimalnim mehanickim svojstvima. U ovom radu opisan je eksperimentalni pristup koji je koriscen za optimizaciju obrade SiC praha velicine 100 nm i bio fokusiran na cetiri faktora sinterovanja: temperatura, vreme, pritisak i brzina zagrevanja. Promenljive su ukljucivale gustinu sinterovanja i mehanicka svojstva. Primenjen je pristup L9 upravne matrice ukljucujuci signal/smetnje (S/N) odnos i analizu varijanse (ANOVA) na optimizaciju faktora obrade. Svi faktori sinterovanja su imali znacajan uticaj na gustinu i mehanicka svojstva. Finalna gustina od 98.1% je dobijena na temperaturi od 1600?C, vreme drzanja od 30 min, pritisak od 50 MRa i brzinu zagrevanja od 100?C-min. Tvrdoca je dostizala 18.4 GPa sa otpornoscu na lom od 4.6 MPa?m i ovo je uporedljivo rezultatima drugih istrazivanja na visim temperaturama konsolidacije.