For standard part Square Bolt, most parts need to be galvanized. Traditional galvanizing methods rely on manual binding and hanging parts one by one. This manual suspension electroplating method has low production efficiency and high labor intensity, and cannot meet the growing demand for aerospace production tasks.
The barrel plating of hexagon bolts is also called barrel plating. It is an electroplating method in which a certain number of small parts are placed in a special cylinder, and various metal or alloy coatings are deposited on the surface of the part through indirect conduction in the rolled state to achieve surface protection and decoration and various functions use. The drum rotates in a certain direction at a certain speed, and the parts continuously roll and descend after rotating in the drum. At the same time, the deposited metal ions are reduced to a metal coating on the surface of the part by an electric field. The fresh solution outside the drum is continuously replenished to the drum through a plurality of holes in the drum wall, and the old liquid in the drum and the gas generated during the plating process are discharged out of the drum through these holes.
1) Measure the thickness of the coating on the hex bolt. The thickness of the galvanized layer was measured by a UTX850C X-ray fluorescence thickness gauge. Since the thickness gauge can only measure the thickness of the coating at or near the plane, it cannot measure the thickness of the coating at the location of the screw. Herein, the thickness of the coating at the upper end of the screw position is measured.
2) Sampling rules for hexagon bolts. When a large number of bolts are plated by barrel plating, the number of standard parts is very large, and 50 products are randomly selected in each batch. An X-ray fluorescence thickness gauge was used to measure the points on each product, and the average thickness of 50 bolts was taken as the average thickness of the coating of the batch of products.
3) Hex bolt thickness uniformity. The uniformity of product thickness can be reflected by the standard deviation of product thickness. The larger the standard deviation, the more uneven the coating thickness between parts; the smaller the standard deviation, the more uniform the coating thickness between parts. Therefore, Hex Bolt Manufacturer must ensure the uniformity of the coating when coating the product.