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NIST High Temp. Superconducting Materials (HTS) Database:

NIST Standard Reference Database 62

Last Update to Data Content: 1996

DOI: https://doi.org/10.18434/T4KP8J

Bibliographic Information

Title: Effect of Y2BaCuO5 on Fracture Toughness of YBCO Prepared by a MPMG Process
Author(s): H. Fujimoto, M. Murakami, and N. Koshizuka
Publication: Physica C Volume: 203 Issue: Not Available Year: 1992 Page(s): 103-110
Editor(s): Not Available
Publisher: Elsevier Science Publishers B.V.
Language: English
Notes: Not Available
Keywords: Material Specification, Hardness, Fracture Toughness

Materials and Properties

Y:123; [Y-Ba-Cu-O]
Material Specification for Y:123; [Y-Ba-Cu-O] Process: Melt Processed
Notes: "Two kinds of YBaCuO samples with and without the 211 phase were prepared by using appropriate amounts of mixtures of Y2O3, BaCO3 and CuO powders. The powders were calcined at 900 °C, then melted at 1400 °C and rapidly cooled down to room temperature. After the melted oxides were pulverized and pressed into pellets, the samples were reheated to 1100 °C and cooled slowly to room temperature. At the final stage, the samples were annealed at 600 °C and cooled down to room temperature in flowing oxygen. The samples were polycrystals with a grain size of approximately 5-10 mm and the shape was cylindrical 20 mm in diameter and 5 mm in thickness... The 211 particles are trapped in the 123 phase through a peritectic reaction, and are finely and homogeneously dispersed in the 123 phase..."
Formula: YBa2Cu3O7-x•wY:211
Informal Name: Y:123
Chemical Family: Y-Ba-Cu-O
Chemical Class: Oxide
Structure Type: Polycrystalline
Manufacturer: In House
Commercial Name: In House
Production Date:
Lot Number:
Production Form:

Hardness for Y:123; [Y-Ba-Cu-O]
Mass Fraction of 211 Phase (%) Hardness (GPa)
0 7.35
Measurement Method: Vickers indentation
"Measurements of the fracture toughness of the 123 phase were made on the (001) plane and a plane perpendicular to the (001) plane, using the indentation fracture method. A total of at least five indentations were made on a sample surface for each contact load, with a Vickers diamond pyramid in ambient air at room temperature. ... Contact loads were between 25 g and 300 g for the 123 matrix, and between 25 g and 500 g for the 123 sample with the 211 particles. The peak load contact time was 15 s. Orientation of the diagonals of the square impression of indentations was parallel to the [100] and [010] directions on the (001) plane, and was parallel and perpendicular to the [001] direction on a plane perpendicular to the (001) plane."

Cautions: Evaluated Data
Fracture Toughness for Y:123; [Y-Ba-Cu-O]
Mass Fraction of 211 Phase (%) Environment () Minimum Toughness (MPa·m1/2) Maximum Toughness (MPa·m1/2) Fracture Toughness (MPa·m1/2)
0 air 0.61 0.84 0.7
0 inert 0.88 1.20 1.0
25 air 1.15 1.48 1.3
25 inert 1.64 2.10 1.8
Measurement Method: Vickers indentation
"Measurements of the fracture toughness of the 123 phase were made on the (001) plane and a plane perpendicular to the (001) plane, using the indentation fracture method. A total of at least five indentations were made on a sample surface for each contact load, with a Vickers diamond pyramid in ambient air at room temperature. ... Contact loads were between 25 g and 300 g for the 123 matrix, and between 25 g and 500 g for the 123 sample with the 211 particles. The peak load contact time was 15 s. Orientation of the diagonals of the square impression of indentations was parallel to the [100] and [010] directions on the (001) plane, and was parallel and perpendicular to the [001] direction on a plane perpendicular to the (001) plane."

Cautions: Evaluated Data
"In order to determine Kc, an estimate of the modulus/hardness ratio, E/H, is necessary." The authors considered a range of values, 21.4 ≤ E/H ≤ 40, given by results reported in other papers.