Nanometer Ceramics Compound Coating is one kind of new and High-tech surface treatment technique for metal material, which will be used for many fields. The machinery parts perform a super-hard micro hardness, high wear-resistant and corrosive-resistant features by adding Nanometer Ceramics Coating on the surface. We try to applying this coating technology to single screws, to screw elements and barrel liners which are installed in Twin Screw Extruder. As a result we enjoy superior feedback, they praise that “We found a feeling that machines step over with big strides”.
Our engineers and some experts from this field together design this nanometer ceramics com pound coating, which is made from special material and HIP technical method. It retains the wear-resistance, corrosion-resistance and oxidation-resistance features from ordinary ceramics amorphous state structure; This coating is also multi-compounded by ceramics and transition metal, so the bonding force between coating and base material and toughness of coating are immensely improved, the internal stress of coating brings down sharply, consequently the inherent brittleness of ceramics is controlled to some extent, this strongly improves its fatigue resistance, extend the useful time of the machinery parts. Compare with normal cermet coating, nanometer coating is more symmetrical, and has a stronger bond of its film-base.
At the time one single screw and screw elements is quick-rotating in the various of inner sleeves inside segment barrels, there will be shearing abrasion between these parts and materials. Besides, contact wear also exists between the surface of a screw & screw elements and inner wall of liners. As the lower friction coefficient of nanometer ceramics compound coating, that’s to say better self-lubricating feature can obviously improve this contact wear, make the abrasion loss of screw & screw elements reduced sharply. After experiment, we find the wear-resistant feature of this nanometer ceramics compound coating is 6 times of ordinary chrome plating, is 4 times of ordinary titanium plating! Its corrosive-resistant feature is also significantly higher than hard-chrome plating or titanium plating generated by charged ions exchange.
The screws we manufacture in nitriding way(Base material 38CrMoAl), and the screw elements made of High Speed Steel(HSS) and after vacuum hardening, are coated with 0.020mm nanometer ceramics compound layer, to be delivered to our clients. Shortly later, the client’s response come: The service life of these screws and screw elements with nanometer ceramics compound layer is at least one more time than those without this coating.