Telecurso 2000 - Processos de Fabricação - 59 Brunimento, lapidação e polimento

Summary

This telecourse covers advanced techniques in manufacturing processes, focusing on operations like burnishing, lapping, and polishing to achieve high-quality finishes on machined parts. The video explains how irregularities like scratches and grooves on parts can be minimized through these operations, enhancing their precision and appearance. Using mechanical abrasion methods such as burnishing, lapping with abrasive powders, and polishing with abrasive discs, these processes are essential for producing smooth, precise, and visually appealing surfaces. The course highlights the importance of these techniques in industries like automotive and tooling, emphasizing both manual and machine-assisted methods.

Takeaways

• 😀 Brunimento (burnishing) is a mechanical machining process that uses an abrasive tool to smooth internal surfaces of a part, achieving a near-perfect finish.
• 😀 Lapidação (lapping) is used to provide an extremely fine finish to mechanical parts by rubbing them against an abrasive liquid and surface, often with diamond abrasives.
• 😀 Polimento (polishing) creates a smooth, shiny surface on parts to improve appearance and protect against corrosion, commonly used for plating preparations like chrome or nickel.
• 😀 Abrasive processes like brunimento, lapidação, and polimento aim to eliminate surface irregularities, improving the precision and aesthetics of machine parts.
• 😀 A part processed by brunimento, like a compressor housing, can achieve a smooth internal surface for better mechanical function, like hydraulic cylinders and engine parts.
• 😀 Polishing can be done manually using fine abrasives or machines using abrasive disks, with radial and axial methods depending on the type of piece and finish required.
• 😀 The purpose of lapidação is to achieve a very fine level of precision and finish, often using hard abrasives such as diamonds for tougher materials.
• 😀 Polimento is important not just for visual appeal, but also for enhancing part durability by preventing corrosion and ensuring a fine finish for manufacturing processes.
• 😀 The quality of polishing depends on the granularity of the abrasive material and the skill of the technician, especially for manual polishing jobs.
• 😀 The Teleaula focuses on specialized machining operations such as brunimento, lapidação, and polimento, which are essential for achieving high-precision, aesthetically finished industrial parts.

Q & A

What is the primary focus of the Teleaula discussed in the script?

The main focus is on the processes of finishing techniques in manufacturing, such as brunimento (burnishing), lapidação (lapping), polimento (polishing), super finishing, and rodagem (running-in).

What is brunimento, and how does it work?

Brunimento is a mechanical machining process that uses abrasive materials to smooth internal surfaces of pieces. A tool called a brunidor, which has abrasive segments, rotates and moves up and down to gradually wear down the surface, creating a nearly perfect finish.

How is lapidação (lapping) different from the jewelry process of lapidation?

In the mechanical context, lapidação refers to achieving precision and a high level of surface finish by using abrasive powders in a liquid medium, creating a smooth and shiny surface. This process is similar to the jewelry process but is focused on achieving mechanical accuracy.

Why is diamond powder used in lapidação?

Diamond powder is used in lapidação due to its extreme hardness. The hardness of the abrasive powder must match or exceed that of the material being worked on, making diamond powder ideal for harder materials.

What role does polimento (polishing) play in the manufacturing process?

Polishing is used to achieve a smooth and shiny surface, improving the appearance of a piece. It also serves to protect the piece's surface from corrosion and can be used to prepare the piece for galvanic processes like plating.

What is the key difference between the industrial polishing and car polishing process?

While both processes aim to achieve a smooth surface, industrial polishing involves mechanical removal of material to create a homogeneous, smooth surface, whereas car polishing typically uses abrasive compounds to restore the paint surface's appearance without removing much material.

What are the two main types of polishing techniques mentioned in the script?

The two main types of polishing techniques are radial polishing, where the abrasive disk rotates around a central axis, and axial polishing, where the abrasive disk rotates along its own axis to polish the surface.

How is manual polishing different from industrial polishing?

Manual polishing involves using abrasives like fine sandpaper, powder, or sticks to polish a surface by hand, requiring significant skill and a high level of craftsmanship, while industrial polishing typically uses automated machines to achieve consistent results more efficiently.

What are the key principles of polishing?

The key principles of polishing include using abrasive tools that rotate at speeds between 45 and 50 meters per second. The surface material is gradually removed according to the grain size of the abrasive, achieving a smooth and shiny finish.

Why is it important for molds in plastic production to be well-polished?

Molds used in plastic production must be well-polished to ensure that the resulting plastic products have a flawless finish. A smooth mold surface ensures that the molded products are free from imperfections and have the desired aesthetic quality.