Explanation

A measure to characterize the impact strength of macromolecule materials. It is used to study the behavior of notched specimen with specified size under specified impact force, and estimate the degree of brittleness or toughness of hard materials under specified conditions. The principle of this method is to place the sample on the specified position of the pendulum impact testing machine, then let the pendulum fall freely, apply impact bending load to the sample to break the sample, and use the energy consumed per unit of original cross-sectional area at the notch when the sample breaks as the impact strength, expressed in kJ/m2, to evaluate the impact toughness of materials. When measuring, the first step is to measure the size of the sample. Before the test, each sample should be carefully measured. For samples with notches, the residual degree at the notch should be measured to an accuracy of 0.02mm. The width and thickness dimensions of each sample should be measured at three points, and the average value should be calculated; Then, according to the impact toughness of the sample, select the appropriate energy pendulum. The large pendulum selected should make the energy consumed by the fracture of the sample within the range of 10% -80% of the total pendulum reserves; Then raise the pendulum of the testing machine, conduct an air impact test, and lower the pendulum to impact three times, observing whether the pointer indicates zero; During impact, the pendulum head of the pendulum shall contact the entire width of the sample phase, and the contact line shall be perpendicular to the longitudinal axis of the sample. When the pendulum impacts and swings back, it stops swinging and records the value of the dial.

Classification