JB/T 7609-1994 Test method for impact strength of carbon graphite materials JB/T7609-1994 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Test Method for Impact Strength of Carbon Graphite Materials JB/T7609-1994
This standard refers to the international standard ISO179:1982 (E) "Determination Method for Pendulum Impact Strength of Hard Plastics". 1 Subject Content and Scope of Application
This standard specifies the principle, test equipment, test conditions, test steps, calculation of results, etc. of the test method for impact strength of carbon graphite materials.
This standard is applicable to the determination of impact strength of carbon graphite materials. 2 Reference Standards
GB1994.1 Test Method for Physical and Chemical Properties of Electric Carbon Products Specimen Processing Technology Regulations 3 Principle
Impact strength is expressed by the ratio of the energy difference (i.e., impact work) of the pendulum before and after the impact to the cross-sectional area of ​​the specimen. 4 Test Equipment
Impact Testing Machine: The pendulum energy is 0.2~0.5J, and the accuracy is 1%. a.
b. Vernier caliper, precision 0.02 mm. c. Micrometer, precision 0.01 mm.
5 Samples
5.1 Sample preparation shall be carried out in accordance with GB1994.1.
5.2 Sample dimensions 6×W×L, mm; 6×6×48. 6 Test conditions
6.1 The pendulum blade angle is 30±1°, and the blade radius is 2mm±0.5mm. 6.1.1 Add a gasket behind the sample so that the blade just contacts the sample striking surface when the pendulum falls. 6.1.2 When the pendulum blade strikes the sample, the deviation between the blade and the sample contact line and the longitudinal axis of the sample is within the range of ±2°. 6.2 The radius of the support corner is 1mm±0.1mm. The two sample support surfaces shall be on the same plane, and when the sample is impacted, the hammer blade surface shall touch the entire width of the sample and be parallel to the sample impact surface. 6.3 The geometric dimensions of the pendulum cutter, the specimen and the support and their relationship are shown in the figure below. 6.4 The impact energy consumed to break the specimen should be between 10% and 90% of the maximum energy of the pendulum. 6.5 The support span is 20 mm.
6.6 The pendulum impact speed is 2.9 m/s.
6.7 The pendulum energy is 0.2 to 0.5 J.
6.8 Test temperature: room temperature.
Approved by the Ministry of Machinery Industry on December 9, 1994
Implemented on June 1, 1995
7 Test steps
JB/T7609—1994
30°±1°
10°±1°
10'±1
1—Pendulum cutter; 2 Specimen, 3—Support
Relationship between pendulum cutter, specimen and support Figure 7.1 Measure the specimen size with a vernier caliper or a micrometer. 7.2 Adjust the testing machine to the horizontal level and adjust the span with the span finder. 7.3 Place the specimen on the support so that the impact direction is parallel to the pressure surface direction of the specimen, the center of the specimen is aligned with the center of the impact hammer, and the distance between the two centers should be within ±0.5mm. 7.4 Raise the pendulum and lock it, check and adjust the pointer of the testing machine so that it points to zero. 7.5 Move the handle steadily to make the pendulum impact the sample until the sample breaks, and read the impact energy consumed when the sample breaks. 8 Result calculation
8.1 Impact strength is calculated according to the following formula
Where: ak—impact strength J/mm; As—impact energy absorbed by the sample, J;
F is the cross-sectional area of ​​the sample, mm\. bzxz.net
8.2 The calculation result should be retained to two decimal places. Additional remarks:
This standard is proposed and managed by Harbin Electric Carbon Research Institute of the Ministry of Machinery Industry. This standard is drafted by Harbin Electric Carbon Research Institute. The main drafters of this standard are Liu Guixiang and Li Xiaoping. 438
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