Paint film impact meter to determine the bonding strength of coating

Bonding strength test, for the sprayed coating, the bonding strength includes the degree of bonding between the coating and the body, and the degree of bonding between the particles of the coating. A qualitative measurement method is the impact test method, also known as the drop hammer impact test method, as shown in Figure 6-26, the weight of the hammer is 500 grams, and the same part of 4 pieces is tested from a height of 100 mm. Repeated hammering to qualitatively test the bonding performance of the layer. The thickness of the 4 pieces should be more than two millimeters, and they should be adjusted to the vertical vertical position at any time during the random test process to paint glass stones. The number of random times is used as the test standard. This method is often used on the spray coating. The second method is the falling ball impact test method. The four pieces are placed at an angle of 45 degrees to the horizontal plane, and a bearing steel ball with a diameter of 40 mm is placed, and they are dropped vertically from a height of one meter to impact the four pieces. The sheet should be fixed well to prevent the impact point from moving. In addition, when the steel ball falls, it should be guided by a guide device. The number of times the ball falls can be used as the basis for judging the coating bonding skill. For ceramic coatings, coating cracking or coating can also be used. The impact absorption energy of glass stone is used to evaluate the impact resistance of coated jewelry.

In addition, when the thickness of the ceramic coating sample is small, it may cause the deformation of the substrate, which makes it difficult to compare the impact absorption energy with each other. Therefore, the substrate is required to have a certain thickness, and the thickness of the ceramic coating should also be within A certain fixed value is different due to different composition thickness and impact resistance absorption energy.

Another method is the vibrator-type impact test. The vibrator-type weight impacts the soil layer, and the combination of the layer sample is characterized by the cracking of the layer or the impact absorption energy of the glass stone. This method is useful for evaluating ceramics. The bonding state of thermal sprayed coatings is more suitable. The impact test method mentioned above generally only detects thermal sprayed coatings. If the impact testing machine is properly modified, it can also be used to detect the bonding performance of brush-plated coatings. , the specific method is to transform the impact head into a ball with a diameter of 5 mm in order to produce traces that can be identified one by one. Selecting a suitable impact force can better evaluate the bonding of the brush coating, but this test method is not suitable for evaluation Soft and plastic brush coating.