8. Tolerance of Form and Position
Form and position tolerances, also known as geometric tolerances, include shape tolerances and position tolerances. Any part is made up of points, lines and surfaces, which are called elements. There are always errors between the actual element and the ideal element after machining, including shape error and position error. This kind of error affects the function of mechanical products, the corresponding tolerance should be specified in the design and marked on the drawing according to the specified standard symbols.
9. Neutral Salt Spray Test (NSS)
Salt spray test is a kind of environmental test that mainly uses artificial simulated salt spray environmental conditions created by salt spray test equipment to assess the corrosion resistance of products or metal materials. It is divided into neutral salt spray and acid salt spray. The difference lies in the different standards and test methods, also known as "NSS" and "CASS" test. Sintered ndFeb neutral salt spray test, according to the national standard using continuous spray test, test conditions are: 35℃±2℃, 5%±1%NaCl solution (mass fraction) and the pH of collected salt spray sedimentation solution ranged from 6.5 to 7.2. The test results were affected by the Angle of sample placement, and the inclined Angle of sample surface placed in the salt spray tank was 45°±5°.
10.Humidity and Heat Test
Sintered Ndfeb wet heat test is a test method to evaluate the effect of sample resistance to wet heat deterioration in an accelerated way. The sample is subjected to high unsaturated wet heat steam pressure in a long time. The test conditions were as follows: temperature 85℃±2℃, relative humidity 85%±5%, humidification water was distilled or deionized water. Severity level 1 is 168 hours.
11. High Pressure Accelerated Aging Test (PTC)
High pressure accelerated aging test is generally called pressure cooker cooking test or saturated steam test. It is mainly to test the high humidity resistance of the sample under harsh temperature, saturated humidity and pressure environment.
The high pressure accelerated aging test of sintered NdFeb is to put the sample into the high pressure accelerated aging test equipment containing distilled water or deionized water with a resistivity greater than 1.0MΩ·cm.
