Development of Physical Models Describing Changes in Tightening Performance due to Thermal Stress under Thermal Shock Test Condition and Experimental Verification

In this study, the binding performance of a Cercon-based zirconia framework material and special Cercon Ceram S zirconia veneering porcelain is discussed. Rectangular 30 mm × 20 mm × 2 mm porcelain blocks were made from zirconia using the CAD/CAM system. The 2 mm veneering porcelain was then sintered onto blocks at a temperature of 850-800°C with a loading speed of l mm/min. The shear bond strength of the interface was tested. Sintering was studied by visual observation, scanning electron microscopy, energy dispersive spectroscopy (EDS), thermal shock test and other methods. Excellent sintering results of the zirconia framework material and veneering porcelain can be achieved. The cross-sectional morphology of the samples, observed by SEM, shows a uniform, fine, and smooth texture for the veneering porcelain, whereas that of the zirconia framework material shows a rough surface with a uniform and compact texture. EDS results indicate that a small amount of A12O3 and SiO2 is present in the zirconia area, and no ZrO2 or Y2O3 is detected in the veneering porcelain area. No interlayer radial crack or flaw is found throughout the entire thermal shock test of the samples at 60-240°C. Thus, the cracking temperature of the samples is pegged at T>240°C. The shear bond strength of the interface is 32.62±5.77 MPa. Chemical element infiltration exists between zirconia and the veneering porcelain, indicating the chemical bond between the two. An excellent match between the Cercon-based zirconia framework and the special veneering porcelain can be achieved, which can satisfy clinical requirements.

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Thermal shock test specimen

10.2172/4223035 ◽

1966 ◽

Author(s):

A.G. Eggers

Keyword(s):

Thermal Shock ◽

Test Specimen ◽

Thermal Shock Test ◽

Shock Test

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Critical analysis and innovation propositions to the heat and thermal shock test method of the Brazilian Standard NBR 15575 (2013)

Revista ALCONPAT ◽

10.21041/ra.v10i3.390 ◽

2020 ◽

Vol 10 (3) ◽

pp. 364-376

Author(s):

Luciani Somensi Lorenzi ◽

Kassio J. Stein ◽

Luiz Carlos Pinto da Silva Filho

Keyword(s):

Thermal Shock ◽

Construction Industry ◽

Visual Inspection ◽

Meta Analysis ◽

Test Method ◽

Thermal Shock Test ◽

Shock Test ◽

Lack Of Information ◽

Number Of Cycles ◽

Brazilian Standard

The tests of Brazilian Standard NBR 15575: 2013 are part of the knowledge of the civil construction industry, but the heat and thermal shock test is innovative and does not have a consolidated history. The research objective is to analyze the testing critically and present proposals based on data meta-analysis. Results showed that the test is very inaccurate in describing the procedure and equipment. This study proposed adjustments and innovations in the test to provide more reliable results, but it does not make propositions regarding visual inspection and the number of cycles. The study concluded that the lack of information on the testing has direct responsibility for the results and that the suggested proposals have the potential to be incorporated.

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