Direct foaming of macroporous ceramics containing colloidal alumina

Autor(es)

Finhana, I. C. ^[1] ; Machado, V. V. S. ^[1] ; Santos Jr, T. ; Borges, O. H. ^{[2, 3]} ; Salvini, V. R. ^[4] ; Pandolfelli, V. C. ^{[2, 3]}

Afiliação do(s) autor(es)

^[1] Fed Univ Sao Carlos UFSCar, Mat Engn Dept, FIRE Associate Lab, Mat Microstruct Engn Grp GEMM, Rodovia Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[2] Santos Jr, Jr., T., Univ Fed Sao Carlos, Grad Program Mat Sci & Engn, Sao Carlos, SP - Brazil

^[3] Santos Jr, Jr., T., Fed Univ Sao Carlos UFSCar, Mat Engn Dept, FIRE Associate Lab, Mat Microstruct Engn Grp GEMM, Rodovia Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[4] Coll Technol FATEC, Jordao Borghetti St 480, BR-14160050 Sertaozinho, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: CERAMICS INTERNATIONAL; v. 47, n. 11, p. 15237-15244, JUN 1 2021.
• Citações Web of Science: 1

Resumo

Liquid foams containing Al2O3 nanoparticles were obtained after direct foaming of a colloidal alumina suspension with ammonium stearate. These systems were stable for at least 24 h and were comprised by small cells (35 mu m). Up to 10 wt% of these foams were added to an ultrastable Al2O3-stabilised one and resulted in macroporous samples with high total porosity (>70%). Their green mechanical strength was proportional to the amount of colloidal alumina added, but lower than a composition with calcium aluminate cement. When compared with compositions prepared with colloidal alumina suspension, the colloidal foams resulted in samples with a higher number of small pores (<30 mu m) and lower linear shrinkage after firing at 1600 degrees C for 5 h (similar to 9%). Thus, colloidal alumina foams can be used for processing macroporous refractory ceramics with smaller pores, lower dimensional changes after firing and higher porosity. (AU)

• Processo FAPESP: 18/07745-5 - Controle dimensional de cerâmicas macroporosas por meio da formação de CA6 in situ
• Beneficiário: Otávio Henrique Borges
• Modalidade de apoio: Bolsas no Brasil - Mestrado