Aprenda os processos de CONFORMAÇÃO / FABRICAÇÃO - Laminação, trefilação, extrusão e forjamento

Summary

In this video, Professor Emanuel provides an in-depth explanation of mechanical forming processes, differentiating between metallurgical and mechanical methods. He covers the principles of plastic deformation and machining, highlighting key processes like forging, extrusion, and drawing. The professor discusses how these methods can alter the shape, mechanical properties, and surface characteristics of materials. Key objectives include enhancing material properties, reducing roughness, and improving strength. He also compares cold and hot deformation processes, emphasizing the importance of temperature control in material shaping. Practical examples of applications in industry are also explored.

Takeaways

• 😀 Processes of mechanical shaping can be divided into mechanical and metallurgical processes.
• 😀 Metallurgical processes involve high temperatures above the melting point to melt and solidify materials into new shapes, including casting, continuous casting, and welding.
• 😀 Mechanical processes shape materials without melting them, typically through plastic deformation or machining, which doesn't require fusion or agglomeration of the material.
• 😀 Plastic deformation involves applying stress greater than the material's yield point but less than its tensile strength, changing its shape without breaking.
• 😀 The course focuses on plastic deformation processes like forging, extrusion, drawing, and stamping.
• 😀 The primary goal of mechanical shaping is to change the material’s dimensions and shape, which can also alter its mechanical properties and surface characteristics.
• 😀 Different processes like rolling, drawing, and extrusion are used depending on the desired shape of the final product, such as sheets, wires, or profiles.
• 😀 Rolling involves passing material between rotating cylinders, commonly used to reduce thickness, while drawing reduces the diameter of materials through a die.
• 😀 Extrusion is similar to drawing but pushes material through a die to form complex profiles.
• 😀 Forging involves applying force, either by pressing or hammering, to shape materials, often used to create parts like small diameter nuts or large shafts.
• 😀 Shaping can be done hot (above recrystallization temperature) or cold (below recrystallization temperature), affecting the material’s grain structure and mechanical properties.

Q & A

What is the primary distinction between metallurgical and mechanical forming processes?

Metallurgical processes involve the use of heat to melt and solidify materials, such as casting, ingotting, and welding. Mechanical forming, on the other hand, uses force to reshape materials without melting, focusing on plastic deformation or machining.

What is the role of sintering in metallurgical processes?

Sintering involves heating fine metal powders below their melting point to allow atomic diffusion, causing the particles to bond together and form a solid material without fully melting.

What does plastic deformation mean in mechanical forming?

Plastic deformation occurs when a material is subjected to stress greater than its elastic limit but less than its rupture point, causing it to permanently change shape, such as in forging or extrusion.

How do machining processes differ from plastic deformation?

Machining processes, like turning and milling, involve cutting the material and typically apply a force that exceeds the material’s rupture limit. In contrast, plastic deformation involves reshaping the material without exceeding its rupture limit, but applying enough force to go beyond its elastic limit.

What are the main objectives of mechanical forming processes?

The primary goals of mechanical forming processes are to alter the shape and dimensions of materials, modify mechanical properties, and improve surface conditions for better performance or aesthetics.

What are the differences between hot and cold forming?

Cold forming occurs below the recrystallization temperature, leading to increased material strength due to strain hardening (work hardening). In contrast, hot forming occurs above the recrystallization temperature, which allows the material to deform more easily but without hardening.

How does rolling work in the lamination process?

Rolling in the lamination process involves passing material between two rotating cylinders, which compress it and reduce its thickness, similar to rolling dough. In some cases, additional support cylinders are used to handle high pressures.

What is the purpose of extrusion in material forming?

Extrusion involves forcing material through a mold to create complex profiles. Unlike rolling or forging, the material is pushed through the die, which gives it the desired cross-sectional shape.

How does the drawing process (trefilação) differ from extrusion?

In drawing (trefilação), the material is pulled through a die to reduce its diameter, while in extrusion, the material is pushed through the die. Drawing primarily focuses on producing thin wires or rods.

What are the typical products of the forging process?

Forging produces high-strength parts like bolts, gears, and shafts through the application of compressive force using a press or hammer. These products can be made in both open and closed dies.