The Service of a Hard Coating on Wire and Tube Manufacturing MoldsThe Service of a Hard and Wear Resistant Coating on Wire and Tube Manufacturing Molds
In the drawing process, the cross-sectional area and/or the shape of a rod, bar, tube, or wire is reduced by pulling through a die. This process causes excellent surface finishes and closely controlled dimensions to be obtained in long products that have constant cross section. In drawing, a pre-formed (extruded and rolled) product with a solid or hollow cross section is pulled through a die at exit speeds as high as several thousand feet per minute or more. The die geometry determines the final dimensions. In general, all forming dies should fulfill some properties such as resistance to plastic deformation, thermal shock, mechanical and thermal fatigue, adhesive and abrasive wear. To achieve better wear resistance, lubricant and hard coatings can be used. Lubrication in the drawing process is essential for maintaining good surface finish and long die life. In some cases, a successful way to minimize the consumption of lubricants is use of PVD hard coatings. Reduction of lubricants increases working speed up and causes reduction of washing processes. These makes the production costs lower and decrease the environmental charge. Nitride coatings as under layers play an important role to attain strong bonding, higher fatigue strength, and superior resistance to cyclic loads and compression. The coating as a top layer is needed to have oxidation and wear resistance. Especially the coatings for drawing dies which expose to a combination of complex wear, fatigue, and lubrication problems in addition to high-temperature exposure. The most widely used coatings in this field are CrN coatings. Other coatings such as TiAlN, TiN or multilayer of these coatings are also used for these applications. Nanostructured coatings are developed to achieve better properties.
- Coatings for Drawing die to produce wire, rod and tube
- Increment of wear resistance and reduction of lubricants use
Abrasion and wear resistant nanostructured coatings
Increment of hardness and abrasion resistance due to nanometric structure of coatings
Standard Date : 2015/07/30
Expire Date : 2018/07/29