Product reliability analysis what are the effects of high and low temperature on product reliability?

Date：2022-06-01 14:49:49Views：717

High and low temperature test, also known as high and low temperature cycle test, is one of the environmental reliability tests. Basically, all products are stored or operated at a certain temperature. In some environments, the temperature will change from high to low. This changing temperature environment will affect the function, performance, quality and service life of the product, accelerate the aging of the product and shorten the service life of the product. If the product is in such a high-temperature and low-temperature environment with large alternating changes for a long time, it needs to have sufficient resistance to high-temperature and low-temperature cycles. In this way, we need to simulate certain environmental conditions to test the products at high and low temperatures. High and low temperature test is a necessary test item for product reliability. What is the impact of high and low temperature test on the product?

1、 Effect of low temperature on products

1. The elasticity of flexible materials such as rubber decreases and cracks occur;

2. Increased brittleness of metals and plastics, resulting in cracking or cracks;

3. Due to different shrinkage coefficients of materials, when the temperature change rate is large, the moving parts will be stuck or the rotation will not work properly;

4. The lubricant viscosity increases or solidifies, and the friction between moving parts increases, causing the action to slow down or even stop working;

5. The electrical parameters of components change, affecting the electrical performance of the product;

6. Icing or frosting causes product structure damage or moisture, etc.

2、 Low temperature environmental effect

1. Harden and embrittle the material.

2. The parts are stuck due to different shrinkage characteristics of different materials.

3. Loss of lubrication due to increased viscosity of lubricant.

4. Electrical property change (such as resistance, capacitance, etc.).

5. Transformer and electromechanical component function change.

6. The impact base becomes hard.

7. Rupture of explosives, such as ammonium nitrate.

8. Make the test piece crack, embrittle, change the impact strength and reduce the strength.

9. Static fatigue occurs in the glass.

10. Condense and freeze water.

11. Reduce human dexterity and degrade hearing and vision.

12. Change the combustion rate.

3、 Effect of high temperature on products

1. The different expansion coefficients of various materials lead to the bonding and migration between materials;

2. Loss of lubricant or reduction of lubrication performance, increasing wear between moving parts;

3. Deformation of sealing packing, gasket, seal, bearing and rotating shaft;

4. Mechanical failure or complete failure due to bonding;

5. The electrical parameters of components change, affecting the electrical performance of the product;

6. Overheating of transformer and electromechanical components;

7. Combustion or explosion caused by flammable or explosive materials;

8. The internal pressure of the seal increases, causing the rupture;

9. Aging, discoloration, blistering, cracking or cracking of organic materials;

10. The insulation performance of insulating materials is reduced.

4、 High temperature environmental effect

1. The parts are stuck due to different expansion characteristics of different materials;

2. The lubricant loses its viscosity, leading to the loss of lubricant and the loss of lubrication of the contact;

3. Change the size of the test piece in whole or in part;

4. Mechanical or total failure due to packaging, gasket, seal, bearing and main shaft becoming skewed, stuck and invalid;

5. Permanent deformation of gasket (gelatinous);

6. Deterioration of air tightness function;

7. Resistance value changes;

8. The stability of the circuit changes with the temperature gradient and the different expansion characteristics of the material;

9. Overheating of transformers and electromechanical components;

10. Change the action / inaction margin of relay and magnetic and hot start components;

11. Reduce the idle time of operation life;

12. The internal crystal structure of solid materials is separated;

13. High pressure is generated inside the closed test piece;

14. Accelerating the combustion of explosives and propellers;

15. Explosive casting shell expansion;

16. Explosive dissolution and exudation;

17. Deterioration and fracture of organic materials.

5、 Influence of temperature change on products

1. The coating layer of components falls off, the potting materials and sealing compounds crack or even break the sealing shell, and the filling material leaks, resulting in the decline of the electrical performance of components;

2. Products made of different materials are heated unevenly when the temperature changes, resulting in product deformation, cracking of sealing products, and breakage of glass or glassware and optical devices;

3. The large temperature difference will cause condensation or frosting on the surface of the product at low temperature, and evaporation or melting at high temperature. Such repeated actions will lead to and accelerate the corrosion of the product.

6、 Environmental effect of temperature change

1. Broken glass products and optical equipment;

2. The movable parts are stuck or loose;

3. Structure separation;

4. Electrical change;

5. Electronic or mechanical failure due to rapid condensation or icing;

6. Fracture in granular or striate form;

7. Different shrinkage or expansion characteristics of different materials;

8. Deformation or fracture of components;

9. Cracking of surface coating;

10. Air leakage of the sealed cabin.