Distribution of Al2O3 reinforcement particles in austenitic stainless steel depending on their size and concentration

Abstract

Achieving a uniform distribution of reinforcement particles within a matrix is one of the challenges that impacts directly on the properties and quality of a composite material. Therefore, the aim of the present work was to investigate the influence of the reinforcing Al2O3 particles' concentration and size on their distribution in reinforced austenite stainless steel. Austenitic stainless steel reinforced with (0.5, 1.0 and 2.5) % of mass fractions of Al2O3 particles was produced by a conventional casting route. In this study, an innovative pre-dispersion approach for the addition of particles into a steel melt was designed. The results of this investigation indicate that the concentration and size of the Al2O3 particles has an impact on the distribution of the reinforcement within the matrix. When the weight percent increased to 2.5 the concentration ratio of the particles' distribution decreases towards the bottom of the cast ingot. In this case also the size of particles starts to play a role, with the larger particle size leading to an increased degree of incorporating particles into the steel matrix. The larger the particles the more particles are found in the cast ingot. Keywords: metal matrix composite, reinforced particles, distribution, conventional casting method Doseganje enakomerne porazdelitve delcev v matrici je eden izmed izzivov, ki direktno vplivajo na lastnosti in kvaliteto kompozitnih materialov. Namen raziskave je bil ugotoviti porazdelitev delcev v mikrostrukturi jekla glede na dodano koncentracijo in velikost. Med procesom konvencionalnega litja avstenitnega nerjavnega jekla so bili dodani delci Al2O3 v ute`nih procentih (0,5, 1,0 in 2,5). V tej {tudiji smo uporabili inovativni pristop dispergiranja delcev pred dodajanjem v jekleno talino. Rezultati raziskave ka`ejo, da je koncentracija in velikost Al2O3 delcev vplivala na porazdelitev delcev v matrici. S pove~anjem ute`nega procenta dodanih delcev na 2,5 se je koncentracijsko razmerje delcev zmanj{alo proti dnu ulitega ingota. V tem primeru ima pomemben vpliv na porazdelitev tudi velikost delcev, ve~ji kot so delci ve~jih je vklju~enih v matrico. Ve~ji kot so delci, ve~se jih nahaja v ulitem ingotu. Klju~ne besede: kovinski kompoziti, utrjevalni delci, porazdelitev, metoda konvencionalnega litja