Temperature shock test-

There are many names for temperature change test projects:

Temperature change, temperature cycle, temperature alternation, rapid temperature change, temperature shock, cold-heat shock, temperature gradient, graded temperature, etc., and the test methods applied in standards of different systems are different. How to distinguish these test items, how to choose test items, which requires an analysis of the sources of each type of test and their differences.

There are two methods for temperature shock testing: gas method and liquid method

There are two implementation methods for the gas method. One is manual conversion, which converts the product between a high temperature box and a low temperature box; the other is an impact test box, which achieves temperature conversion by switching the circulation damper of the cold and hot chambers or other similar means. The upper temperature limit and lower temperature limit are the storage limit temperature values of the product. The liquid method is implemented in a hanging basket type, in which the product is placed in a hanging basket and immersed in liquids at different temperatures as required. It is suitable for glass-metal seals and similar products.

The temperature shock test is an accelerated test that simulates a large number of slow temperature cycles in a vehicle. Corresponding to the actual vehicle temperature cycle, acceleration is feasible with a faster temperature change rate and a wider temperature change range. Failure modes are material cracking or sealing failure due to aging and different temperature expansion coefficients. This test will cause mechanical defects (cracks) and does not require live work.

Carry out rapid temperature changes within a specific time. The conversion time is generally set to 2 to 3 minutes manually, less than 30 seconds automatically, and less than 10 seconds for small samples. The temperature impact test in common terms also belongs to the cold and hot impact test.

There are several important parameters to consider in this test: number of cycles, temperature conversion time, temperature holding time, and temperature limit value (because this test is a storage-type test, its limit value is the storage limit temperature value). The reference parameter settings are shown in the table, and the specific cycle number comes from an empirical value calculated by the accelerated model.