Nonferrous Tool and Die Materials PDF

Faculty of engineering Mechanical Engineering Dept. Materials Engineering III Instructor: Dr. Nariman Ezzat  Faculty of engineering Mechanical Engineering Dept. Nonferrous Tool and Die Materials In this chapter:  The nonferro...

Faculty of engineering Mechanical Engineering Dept. Materials Engineering III Instructor: Dr. Nariman Ezzat  Faculty of engineering Mechanical Engineering Dept. Nonferrous Tool and Die Materials In this chapter:  The nonferrous tool and die materials involved in the metal- forming processes are provided.  The composition and physical properties of the principal materials used in die design for metal forming are discussed.  The emphasis of this chapter will be on the nonferrous materials needed to produce dies for metal forming.  Introduction  A wide range of materials are available to the designer of tools and dies.  No single material is best for all forming applications because of the extensive range of conditions and requirements encountered in various operations. Selecting the proper material for a specific application can:  improve workpiece quality,  increase productivity, and  reduce costs. Factors affecting the selection of a proper die or mold material for a specific application include:  The operations to be performed, including their severity, forces applied, temperatures encountered, and lubricants used.  The workpiece material, including its hardness, thickness, and condition, as well as the size of the workpiece.  The production rate and quantity, accuracy, and finish requirements  The press or machine to be used, including its type and condition  The cost per part produced, based on the material, manufacturing, heat treatment, and maintenance  The design of the die or mold  The accuracy and rigidity of the setup  Costs, as well as the life of the die or mold.  The current availability of the die or mold material  The properties of the material. including resistance to wear, heat, and deformation, and the ease with which it can be machined, heat treated. and ground  The nonferrous materials used in metal working applications, including:  Cemented carbides, which are the most commonly used nonferrous tool and die material  Ceramics  Ultra-hard Tool Materials  Cemented Carbides  Cemented carbides belong to a class of hard, wear-resistant, refractory materials in which the hard carbide particles are bound together or cemented, by a soft and ductile metal hinder.  These materials were first developed in Germany in the early 1920s in response to demands for a die material having sufficient wear resistance for drawing tungsten filament wires to replace the expensive diamond dies then in use.  The first cemented carbide to be produced was tungsten carbide (WC) with a cobalt binder. Although the term cemented carbide is widely used, these materials are better known internationally as hard-metals.  Manufacture of Cemented Carbides  Cemented carbides are manufactured by a powder metallurgy process consisting of a sequence of steps in which each step must he carefully controlled to obtain a final product with the desired properties, microstructure, and performance. The steps include: 1. Processing of the ore and the preparation of the tungsten carbide powder 2. Preparation of the other carbide powders 3. Production (milling) of the powders 4. Compacting or powder consolidation 5. Sintering 6. Postsinter forming The sintered product can be directly used or can he ground, polished, and coated to suit a given application.