Title: Optical and Mechanical Properties of Alumina Ceramic Matrix Composites
Waad Khayat (Presenter)
Henry M. Goldman School of Dental Medicine,Boston University
Richard Pober, Henry M. Goldman School of Dental Medicine,Boston University
Yuwei Fan, Henry M. Goldman School of Dental Medicine,Boston University
Russell Giordano, Henry M. Goldman School of Dental Medicine,Boston University
Objectives: Determine the effect of sintering cycle and curing technique on the optical and mechanical properties of alumina ceramic matrix composites.
Methods: Alumina discs (15mm x 1.5mm) were fabricated by slip casting. Specimens were divided into 7 groups. Groups PH1, H1, M1 were sintered at 1150°C. Groups PH2, H2, M2 were sintered at 1200 °C. Group FD was fully sintered at 1550°C. Density was calculated for each specimen for verification. Groups M1, M2 and FD were the control groups and received no further treatment. Other groups were silanated and dried overnight at 100°C. Then, UDMA-TEGMA resin was prepared and infused into the porous ceramic specimens under vacuum. Groups PH1and PH2 were cured by heat at 90°C and isostatic pressure of 138 MPa. Groups H1 and H2 were cured by heat only at 90°C. Specimens were finished and polished. Visible light transmission was evaluated with spectrophotometer (X-rite Ci7600). Biaxial flexural strength was measured using a universal mechanical testing machine (Instron 5566A) with a crosshead speed of 0.5 mm/min. One-way analysis of variance (ANOVA) was performed for statistical analysis.
Results: Results are shown in Table 1.
Conclusions: Within the limitation of the study, alumina matrix composites that sintered at 1200°C with applied heat and pressure for resin curing showed both high strength that was comparable to the strength of fully dense alumina and high translucency when compared with other experimental groups but still significantly less than the fully dense specimens.