Ouzhan Trade (Shanghai) Co., Ltd.

Machining Introduction

Mechanical processing is a common and all-encompassing process category. The mechanical processing referred to here refers specifically to the processing methods used in surface effect treatment. There is a partial overlap with the mechanical processing in the "Forming Process", and you need to pay attention to the difference.
There are many types of machining. The traditional processing methods are nothing more than turning, milling, planing, grinding, punching, cutting, drilling, etc. Most of these traditional methods are gradually integrated and iterated by modern precision CNC machining centers. Some new technological means are gradually enriched. The space of this book is limited, so I won't list them all here. I will only extract the techniques involved in design practice by designers, such as sandblasting, wire drawing, polishing, stamping, and rolling.

Features
The characteristics of machining can be summarized as: high speed, high efficiency and high precision.
For different machining process methods, their respective characteristics are shown in the following table:

Craft means

Features

Sandblasting

Can be arbitrarily selected between different roughness, so as to obtain different roughness of the workpiece surface

polishing

Can reduce the surface roughness of the workpiece, and get a smooth surface or mirror gloss

Spark discharge

It can process any high-strength, high-hardness, high-toughness, high-brittleness and high-purity conductive materials; there is no obvious mechanical force during processing, and it is suitable for processing low-rigidity workpieces and fine structures

Drawing

It can not only change the original mechanical pattern or surface deficiencies, well cover up the mechanical pattern and mold clamping defects in production, but also has a good appearance decoration effect

Applicable materials

Machining technology

Applicable material

Physical sandblasting

Metal, glass, ceramic

Polishing

Metal, ceramic, glass

Spark discharge

Conductive materials such as metals

Drawing

Metal, acrylic, PC, PET, glass

SandblastingSandblasting
Sandblasting is a process that uses compressed air or water to drive hard particles to strike the surface of the workpiece in a distributed manner to achieve cleanness or roughness. Functional purposes such as rust removal, peeling coating, cleaning, etc. will not be discussed here. The application in appearance technology is mainly discussed here. The general sandblasting process is used to make matte / matte / sand surface.
Sandblasting can be applied to the surface of almost all workpieces including plastics, metals, glass, ceramics, etc., but the most used in mass production is the appearance of sandblasting of metal workpieces, especially stainless steel and aluminum products.

Brushed pattern
Brushed pattern
Wire drawing is almost one of the most common metal decoration processes. The drawing process can be seen on metals, especially stainless steel, ceramics and plastic materials.
Wire drawing generally includes physical grinding, CNC engraving and laser, etc. The effects achieved by different processing methods are also very different, and the cost is also different.

Rolling pattern Rolling pattern
Rolling, also called knurling, is a very old process. A knurling knife is used to add straight or net-like relief patterns on the surface of cylindrical metal workpieces to increase friction and facilitate operation. However, with the needs of the public's aesthetics, the aesthetics of the process has gradually increased, and the decorative function of some products is greater than the practical function.

CNC engraving
CNC engraving
CNC engraving is the use of CNC for turning and engraving on the surface of the workpiece. The brushed and CD patterns produced are clean, orderly and regular. This book is called procedural texture. In addition, CNC engraved textures can also control the depth to produce relief effects.

Polishing
Polishing refers to the use of mechanical, chemical or electrochemical effects to reduce the surface roughness of the workpiece to obtain a bright and smooth surface. It is the use of polishing tools and abrasive particles or other polishing media to modify the surface of the workpiece.

Mechanical polishing
Mechanical polishing is a polishing method that relies on cutting and plastic deformation of the material surface to remove the polished convex parts to obtain a smooth surface. Generally, oil stone sticks, wool wheels, sandpaper, etc. are used, and manual operations are the main ones.
The ultra-precision polishing method can be used for high surface quality requirements. Ultra-precision polishing is the use of special abrasive tools, which are pressed against the processed surface of the workpiece in a polishing liquid containing abrasives for high-speed rotation. Using this technology, the surface roughness of Ra0.008μm can be achieved, which is the highest among various polishing methods. This method is often used in optical lens molds.

Fluid polishing
Fluid polishing relies on high-speed flowing liquid and abrasive particles carried by it to wash the surface of the workpiece to achieve the purpose of polishing. Commonly used methods are: abrasive jet processing, liquid jet processing, hydrodynamic grinding and so on.
Hydrodynamic grinding is driven by hydraulic pressure to make the liquid medium carrying abrasive particles flow back and forth across the surface of the workpiece at high speed. The liquid medium is mainly made of special compounds with good flowability under lower pressure and mixed with abrasives. The abrasives can be made of silicon carbide powder.

Magnetic grinding and polishing
Magnetic abrasive polishing is to use magnetic abrasives to form abrasive brushes under the action of a magnetic field to grind the workpiece. Its advantages are high processing efficiency, good quality, easy control of processing conditions and good working conditions. Using suitable abrasives, the surface roughness can reach Ra0.1μm.


Post time: Sep-25-2020