Materials Engineering III - Nonferrous Tool and Die

Materials Engineering III - Nonferrous Tool and Die Materials

• Course Instructor: Dr. Nariman Ezzat
• Course Title: Materials Engineering III
• Department: Mechanical Engineering
• University: Helwan University

Chapter Overview

• This chapter focuses on nonferrous tool and die materials used in metal-forming processes.
• It discusses the composition and physical properties of key materials used in die design for metal forming.
• The chapter emphasizes nonferrous materials required for producing dies for metal forming processes.

Introduction to Tool and Die Materials

• A wide variety of materials are available for tool and die design.
• No single material is ideal for all forming applications due to the diverse conditions and requirements in various processes.
• Proper material selection is crucial to enhance workpiece quality, increase productivity, and reduce costs.

Metal Forming Processes Overview

• Metal forming processes are divided into Sheet Metalworking and Bulk Deformation.
• Sheet Metalworking: characterized by large surface area/volume ratios (e.g., bending, shearing, deep drawing).
• Bulk Deformation: characterized by small surface area/volume ratios (e.g., rolling, forging, extrusion, wire drawing).

Temperature Ranges in Metal Forming

• Cold Working: temperatures below 0.3 times the melting point of the metal.
• Warm Working: temperatures between 0.3 and 0.5 times the melting point.
• Hot Working: temperatures between 0.5 and 0.75 times the melting point, often at or near the melting point.

Specific Metal Forming Processes

• Bending: straining sheet material to create a bend.
• Deep Drawing: forming a flat sheet into a hollow or concave shape (e.g., a cup).
• Shearing: cutting metal sheets using shearing action.
• Rolling: compressing a slab or plate between rotating rolls to reduce thickness.
• Forging: severe deformation process used to shape metals, often at high temperatures.
• Extrusion: pushing a workpiece into a die opening to take the die opening shape.
• Wire Drawing: similar to extrusion but the workpiece is pulled through a die opening.

Factors Affecting Die/Mold Material Selection

• Operations: severity of the operation, applied forces, temperatures, and the lubricants being used.
• Workpiece Material: hardness, thickness, condition, & workpiece size.
• Production Requirements: rate, quantity, accuracy, and finish.
• Press/Machine: type and condition.
• Cost Considerations: cost per part, die/mold design, accuracy/rigidity of the setup, and the life of the die/mold.
• Material Availability: current availability of the die/mold material.
• Material Properties: wear resistance, heat resistance, deformation resistance, machinability, & heat treatability.

Nonferrous Tool and Die Materials

• Cemented Carbides: hard, wear-resistant, widely used nonferrous tool and die material.
• Ceramics: another category of nonferrous tool and die materials.
• Ultra-hard Tool Materials: specialized/advanced materials.

Cemented Carbide Manufacturing

• Cemented carbides are made via powder metallurgy.
• The process involves careful steps in powder preparation, compaction, sintering, and sometimes post-sintering forming.

Manufacturing Process Steps

• Processing of the ore and preparation of tungsten carbide powder.
• Preparation of other carbide powders.
• Milling of the powders.
• Compaction or powder consolidation.
• Sintering process.
• Post-sintering forming.