FRACTURE TOUGHNESS TESTING
ASTM E399 KIC TEST, ASTM E1820 JIC TESTING & MORE
At Zhejiang Guojian Testing Technology Co., Ltd (CCT) in ZheJiang (CHINA), our skilled team performs Fracture Toughness Tests to evaluate a material's resistance to crack growth under increasing loads. The values obtained from the test are crucial in selecting materials and assessing the likelihood of component failure when a flaw is detected in a structure. Our fracture toughness testing services include KIC testing to ASTM E399, JIC testing to ASTM E1820, and Master Curve testing to ASTM E1921.
SCOPE OF TESTING SERVICES
Fracture toughness testing can be conducted using loads ranging from 40 lbf to 100,000 lbf, and over a wide temperature range from -323°F to 1800°F. To accommodate different specimen sizes and geometries, fixturing is available, including C(T) compact tension and SE(B) single edge bend.
TEST METHODS/SPECIFICATIONS
· ASTM E399
· ASTM E1820
· ASTM E1921
· ASTM E2899
TEST SPECIMENS PREPARED BY Zhejiang Guojian Testing Technology Co., Ltd (CCT)
To conduct the fracture toughness test, it is crucial to have a precisely machined specimen that meets the required specifications. Zhejiang Guojian Testing Technology Co., Ltd (CCT) 's Machine Shop is equipped to prepare specimens for all types of fracture toughness testing and can provide an EDM machined notch.
There are several specimen geometries commonly used in fracture toughness testing, including:
· Single Edge Bend (referred to as SE(B) or SENB) – a rectangular specimen, with a slot cut in the long side, loaded in three point bending.
· Compact Tension (C(T)) – the most commonly used geometry.
· Disk-Shaped Compact Tension (DC(T)) – used when a fracture toughness result is required in the C-R direction of a round bar.
At Zhejiang Guojian Testing Technology Co., Ltd (CCT) , a wide range of specimen sizes can be machined for fracture toughness testing, from SE(B) bars with Charpy dimensions to C(T) specimens as wide as 4.5 inches.
Contact us to discuss your requirements for fracture toughness testing, also known as fracture mechanics testing.
THE FRACTURE TOUGHNESS TEST PROCESS
Fracture toughness is a crucial material property in various design applications as flaws can inevitably occur in materials. These flaws can take the form of cracks, voids, inclusions, weld defects, or design discontinuities.
The fracture toughness test aims to determine the conditions in which an existing crack in a material will extend by measuring the material's resistance to crack extension when a sharp crack is present. This property is obtained by subjecting specimens containing pre-existing cracks or notches to increasing tensile loading conditions. By measuring the load and displacement as the crack lengthens, the material's resistance to further crack extension can be determined.
ASTM E399 / KIC TEST
The KIC test, also known as the K1C fracture toughness test, is a commonly used method for determining fracture toughness according to ASTM E399. This test involves subjecting the specimen to a continuously increasing load until the critical stress intensity, KIc, is determined. The KIC test is widely used in various industries, including the aerospace sector, and is specified in many industry standards.
ASTM E1820 / JIC TESTING AND MORE
The ASTM E1820 standard for fracture toughness testing involves applying a continuously rising load to the specimen with periodic partial unloading to measure the crack length as the test progresses. This method allows for data to be collected throughout the test, providing insight into the behavior of the material as the crack opens. As a result, valid results can often be obtained that would be impossible or impractical with the KIc test.
The ASTM E1820 test method provides fracture toughness values of KJIc and JIc, and can also determine the Crack-Tip Opening Displacement (CTOD, δ) through data analysis. The “J” integral is used to describe elastic-plastic fracture toughness in more ductile materials that can deform and resist crack growth under load. A Roman numeral subscript is added to “K” and “J” to indicate the mode of fracture used in the test, with Mode I fracture being the most common. When a material with a crack reaches a critical value of KIc or JIc under Mode I plane-strain conditions, the crack will start to grow. The experimental values of KIc and JIc can be applied to design structures and ensure that components do not fail due to brittle or ductile fracture. KJIc is derived from the JIc result.
ASTM E1921 / MASTER CURVE TEST
ASTM E1921 is a fracture toughness test that determines the Reference Temperature (To) of certain steels, especially those used in cold weather environments. This method characterizes the fracture toughness of ferritic steels that experience cleavage fracture mechanisms as a function of temperature.
The ASTM E1820 test method is used with some additional requirements, including the need for at least six valid results taken at varying temperatures. These results are analyzed using a Weibull statistical analysis to identify .
PROVIDING INFORMATION AND SAMPLES FOR RELIABLE TESTING
To ensure accurate testing, it is crucial for us to have information regarding the material specification required for testing. If the material is proprietary, we will need a copy of the specification. Otherwise, please provide as much information as possible regarding the intended use of the test data, such as for material conformance, research, comparison, or failure analysis.
In addition, any available material data, such as yield and tensile strength, Young's Modulus, and expected fracture toughness at the desired test temperature, would be useful. Tensile, yield, and Young's Modulus at the test temperature are necessary for performing an ASTM E1820 test.
When submitting samples, please ensure that specimens can be successfully removed from the parent material with the desired orientation. It is important to clearly mark the orientation of the specimen relative to the parent material on the sample.
Zhejiang Guojian Testing Technology Co., Ltd (CCT) CAPABILITIES
· Test Methods – ASTM E399 KIc; ASTM E1820 JIc, KJIc; ASTM E1921, ASTM E2899
· Loads – to 100,000 lbf.
· Temperature – range from -323° F to +1800° F
· Fixturing – SE(B) single edge bend and C(T) compact tension specimen geometries in a range of sizes
· Test Specimens – prepared in Zhejiang Guojian Testing Technology Co., Ltd (CCT) ’s Machine Shop according to standard procedures; EDM notch capabilities
