ASTM C1469-22 - 1.2.2022
 
Significance and Use

5.1?Advanced ceramics can be candidate materials for structural applications requiring high degrees of wear and corrosion resistance, often at elevated temperatures.

5.2?Joints are produced to enhance the performance and applicability of materials. While the joints between similar materials are generally made for manufacturing complex parts and repairing components, those involving dissimilar materials usually are produced to exploit the unique properties of each constituent in the new component. Depending on the joining process, the joint region may be the weakest part of the component. Since under mixed-mode and shear loading the load transfer across the joint requires reasonable shear strength, it is important that the quality and integrity of joint under in-plane shear forces be quantified. Shear strength data are also needed to monitor the development of new and improved joining techniques.

5.3?Shear tests provide information on the strength and deformation of materials under shear stresses.

5.4?This test method may be used for material development, material comparison, quality assurance, characterization, and design data generation.

5.5?For quality control purposes, results derived from standardized shear test specimens may be considered indicative of the response of the material from which they were taken for given primary processing conditions and post-processing heat treatments.

 
1. Scope

1.1?This test method covers the determination of shear strength of joints in advanced ceramics at ambient temperature using asymmetrical four-point flexure. Test specimen geometries, test specimen fabrication methods, testing modes (that is, force or displacement control), testing rates (that is, force or displacement rate), data collection, and reporting procedures are addressed.

1.2?This test method is used to measure shear strength of ceramic joints in test specimens extracted from larger joined pieces by machining. Test specimens fabricated in this way are not expected to warp due to the relaxation of residual stresses but are expected to be much straighter and more uniform dimensionally than butt-jointed test specimens prepared by joining two halves, which is not recommended. In addition, this test method is intended for joints, which have either low or intermediate strengths with respect to the substrate material to be joined. Joints with high strengths should not be tested by this test method because of the high probability of invalid tests resulting from fractures initiating at the reaction points rather than in the joint. Determination of the shear strength of joints using this test method is appropriate particularly for advanced ceramic matrix composite materials but also may be useful for monolithic advanced ceramic materials.

1.3?Values expressed in this test method are in accordance with the International System of Units (SI) and IEEE/ASTM SI 10.

1.4?This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are noted in 8.1.

1.5?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

 
2. Referenced Documents

D3878-23

Standard Terminology for Composite Materials

C1341-13(2023)

Standard Test Method for Flexural Properties of Continuous Fiber-Reinforced Advanced Ceramic Composites

C1275-18

Standard Test Method for Monotonic Tensile Behavior of Continuous Fiber-Reinforced Advanced Ceramics with Solid Rectangular Cross-Section Test Specimens at Ambient Temperature

C1211-18(2023)

Standard Test Method for Flexural Strength of Advanced Ceramics at Elevated Temperatures

E6-23a

Standard Terminology Relating to Methods of Mechanical Testing (Includes all amendments and changes 3/29/2023).

C1161-18(2023)

Standard Test Method for Flexural Strength of Advanced Ceramics at Ambient Temperature

C1145-19

Standard Terminology of Advanced Ceramics

E122-17(2022)

Standard Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot or Process

E4-21

Standard Practices for Force Calibration and Verification of Testing Machines

D5379/D5379M-19e1

Standard Test Method for Shear Properties of Composite Materials by the V-Notched Beam Method (Includes all amendments and changes 3/24/2021).

IEEE/ASTM SI 10

American National Standard for Use of the International System of Units (SI): The Modern Metric System

E337-15(2023)

Standard Test Method for Measuring Humidity with a Psychrometer (the Measurement of Wet- and Dry-Bulb Temperatures)