Fabrication of bulk glass from the eutectic melt in Y2O3-CaO-Al2O3 system

Abstract

We have studied glass formable region in the Y 2 O 3 -CaO-Al 2 O 3 system. An optimal composition for the amorphous phase formation was found in the pseudo-eutectic 12CaO·7Al 2 O 3 -CaYAlO 4 system. An amorphous bulk plate of 10 × 25 × 1.8 mm was successfully fabricated using a simple molding technique. The fabricated glass plate showed an IR absorption edge at around 5.6 μm. The crystallization of the glass sample was observed above 890 • C by an X-ray diffraction (XRD) and Thermogravimetry and Differential thermal analysis (TG-DTA).

Fabrication of Crack‐Free C12A7 Nano‐Ceramics Composite from Eutectic Glass in the C12A7–CaYAlO4 System

“…[15][16][17] Based on new findings on the eutectic solidification in the ternary Al 2 O 3 -Y 2 O 3 -ZrO 2 system 18-20 and amorphous formation in the Al 2 O 3 -Gd 2 O 3 -HfO 2 system, 15,21 we have studied the melt-solidification and amorphous phase formation in the system Al 2 O 3 -CaO-Y 2 O 3 . 22 In the present study, we demonstrate the fabrication of the C12A7 bulk materials with an arbitrary shape and size from the eutectic melts in the pseudobinary C12A7-CaYAlO 4 system, which should have more advantages to fabricate the C12A7 bulk materials than the composition of the stoichiometric C12A7. Ltd., Tokyo, Japan) powders by mixing in ethanol using an alumina mortar and a pestle for 10 min.…”

“…The experimental procedures of the fabrication process by the arc imaging furnace is described in previous reports. 15,[18][19][20][21][22] After heating the sample at 8301C for 15 min in order to remove the residual stress, two parallel flat planes were prepared by mirror polishing on the sample globules in order to measure the precise linear expansion. The linear expansion behavior with crystallization of the glass samples were measured by loading 0.5 g weight, vertical to the mirror planes and at a heating rate of 101C/min from room temperature to 12001C using thermodilatometry (TD) (TD5000SA, Bruker AXS K.K., Tsukuba, Japan).…”

Crystallization behavior of the eutectic glass in the C12A7–CaYAlO4 system

“…Detailed procedures for the arc-image furnace (UF-10001, Ushio Inc., Tokyo, Japan) are mentioned in our previous papers. 4,5,11,16 The sample after the solidification had globule shape due to the surface tension of the melt and vitrified caused by rapid cooling rate about 200-500 • C/s. The sample globules were annealed at several temperatures and several time periods, i.e.…”

“…into the calcium aluminate glass to obtain higher glass formability than pure CaO-Al 2 O 3 glasses. Recently, we have reported a fabrication technique for a bulk of calcium aluminatebased glass in the eutectic Y 2 O 3 -CaO-Al 2 O 3 system, 4 where the glass phase were easily obtained by conventional molding technique and the glass showed high transparency up to ∼5 m. Our research has been based on a ternary eutectic system rather than a binary eutectic. An advantage to using the ternary eutectic is its low melting point and a high glass formability which enables to fabricate bulk ceramics from melt.…”

Fabrication of amorphous bulk and multi-phase ceramics by melting method in the HfO2-Al2O3-Gd2O3-Eu2O3system

“…Since the melting method have higher productivity and shaping ability [1][2][3][4][5][6], we have reinvestigated the melting method particularly for binary and ternary ceramic systems of multi oxides [1][2][3][4]. We have succeeded in obtaining an amorphous phase in the HfO 2 -Al 2 O 3 -Gd 2 O 3 system, not by rapid quenching [5,6] but by simple melt solidification [2][3][4]. In their developments we have found out that the amorphous phase is easier to obtain from quaternary melts than from ternary melts.…”