Metalworking: The Cornerstone of Industrial Design

In the vast field of industrial design, metalworking is an extremely crucial part, providing a solid material foundation for turning products from concepts into reality. From everyday electronic devices to large machinery, the presence of metalworking is ubiquitous. Through a series of precise and diverse processing techniques, designers are able to shape metal materials into products that combine functionality and aesthetic value, meeting the ever-growing demands of people's daily life and production needs.

Common Metalworking Methods
1. Stamping: Stamping is a forming process that relies on a press and die to apply force to sheet metal, strip, pipe, or profile materials, causing plastic deformation or separation to achieve the desired shape and size of the workpiece (stamped part). It is characterized by high processing speed and accuracy and is commonly used in the manufacture of automobile bodies, metal camera bodies, mobile phone shells, and other products. For example, in the automotive industry, the majority of large-scale metal processing is done through stamping. Components such as car bodies, door panels, and trims can be efficiently mass-produced using stamping. The principle is based on the plastic deformation properties of metals: under pressure, metal sheets deform according to the shape of the die.

2. Casting: Casting involves pouring molten metal into a specific mold cavity, allowing it to cool and solidify to obtain a casting that matches the shape of the cavity. This method can produce parts with complex shapes and is widely used in machinery, automotive, aerospace, and other industries. For example, engine blocks, due to their complex internal structures, can be formed in one piece using casting. Depending on different process characteristics, casting can be subdivided into sand casting, metal mold casting, die casting, and others. Sand casting has lower costs and is suitable for single or small batch production; die casting offers high production efficiency and precise dimensions, suitable for high-volume production of small, high-precision parts.

3. Forging: Forging involves applying external force to a workpiece to induce plastic deformation, thereby changing its shape, size, and properties. Forging can refine metal grains and improve the strength and toughness of metals. It is commonly used to manufacture components that bear large loads, such as turbine discs in aircraft engines or crankshafts in cars. Forging can be divided into open-die forging and closed-die forging. Open-die forging is highly flexible, suitable for single or small batch production, while closed-die forging is performed in specialized dies, offering high production efficiency and consistent dimensional accuracy, making it suitable for large-scale production.

4. Machining: Machining involves using cutting tools to remove excess material from a workpiece to obtain parts with specified dimensions, shapes, and surface quality. Machining processes include turning, milling, boring, planing, and grinding. Turning is primarily used for machining rotational surfaces, such as shafts; milling can produce various shapes, including flat surfaces, grooves, and contours; grinding is used for achieving high precision and surface quality, often in the finishing of parts. In precision instrument manufacturing, high-precision machining is frequently required to ensure parts meet dimensional accuracy and surface roughness specifications.

Selection of Metal Processing Techniques

1. Based on product requirements: If the product needs to be mass-produced and the dimensional accuracy requirements are not extremely high, stamping and casting processes are good choices as they can achieve efficient large-scale production and reduce costs. For example, the metal mid-frame of a mobile phone can be produced at tens of pieces per minute using die-casting. For products that require high precision, such as the blades of an aircraft engine, precision grinding and other cutting processes are more suitable, ensuring the complex shape and strict dimensional tolerances of the blades, meeting their operational requirements in high-temperature and high-pressure environments. For small, simple-shaped parts, simple cutting processes like turning may suffice; however, for parts with complex curved surfaces, advanced cutting techniques such as CNC milling or five-axis machining are needed to achieve the designed shape.

2. Considering material properties: Different metals have distinct physical and chemical properties, which determine the suitable processing techniques. Steel, with high hardness and toughness, is suitable for forging and welding. For automotive chassis hardware parts, forging can enhance strength, and welding can assemble individual components into an overall structure. Aluminum, being lightweight and easily formed, is more suitable for stamping and die-casting; for example, aluminum alloy window and door frames can be die-cast into complex shapes in one go, achieving much higher efficiency than other methods. Copper, with excellent electrical conductivity, is often processed by stretching and rolling; copper terminals for wire connectors are produced through stretching to ensure stable conductivity. If the material has extremely high hardness, such as certain special alloy steels, ordinary cutting processes may be very difficult, and special processing methods like electrical discharge machining may be required.

3. Taking cost budget into account: Cost is a critical factor in industrial design. In stamping and die-casting processes, mold costs account for a significant portion, and for small-batch production, the high mold cost can greatly increase expenses. In such cases, processing techniques that do not require molds, such as laser cutting or wire cutting, may be more economical. For large-scale production, although stamping and die-casting have high upfront mold investment, the unit cost decreases significantly with increased production volume. Material utilization during processing also affects cost; for some complex-shaped parts, cutting processes may generate substantial waste, increasing material costs, whereas near-net-shape processes like precision casting can reduce material waste and lower costs. Choosing a cost-effective processing method while meeting product performance requirements can enhance the product's market competitiveness.

Surface Treatment: Giving Metal a New Life
Once metal has acquired its basic shape and structure through processing, surface treatment becomes a key step in giving it new life. Surface treatment not only enhances the corrosion resistance, wear resistance, and other properties of metal products, but also significantly improves their appearance, making them more textured and aesthetically valuable, meeting various users' demands for both functionality and design.

CCommon surface treatment processes
1. Anodizing: Anodizing is an electrochemical reaction process, using metal (mainly aluminum and its alloys) as the anode, electrolyzing in a suitable electrolyte, so that a layer of inorganic oxide film is formed on the surface of the part. In sulfuric acid electrolyte, the aluminum workpiece is used as an anode, and after direct current, the aluminum atoms lose electrons and become aluminum ions into the solution, and the oxygen ions in the solution combine with the aluminum ions to form an alumina film on the surface of the workpiece. This oxide film is tightly bonded to the substrate, does not peel off easily, and has excellent physical and chemical properties. It can significantly enhance the corrosion resistance of metals, and in harsh environments such as oceans and humidity and heat, anodized metal products can effectively resist the erosion of corrosive media such as water vapor, salt spray, acid and alkali, and extend their service life. Like aluminum alloy doors and windows in the field of architectural decoration, they are anodized, which is not only corrosion-resistant, but also maintains their beauty for a long time. The hardness of the oxide film is also high, and in hard anodizing, the hardness can reach more than HV400, which greatly improves the surface wear resistance and is suitable for high-friction scenarios, such as the surface treatment of mechanical parts. Moreover, the anodized metal surface is more uniform and beautiful, and a variety of color options can be realized through dyeing treatment, enhancing the decorativeness and brand recognition of the product.

2. Metal Drawing: Metal drawing is a process that creates a linear texture on a metal surface through physical or chemical methods. From the perspective of the process principle, it is to implement further texturing on the finished metal surface, so that the metal is forced to pass through the mold under the action of external force, and the cross-sectional area of the metal is compressed, so as to obtain the required cross-sectional area shape and size, and form a regular and relatively uniform texture. The wire drawing process can change the original mechanical pattern or surface deficiencies, well cover up the mechanical pattern and clamping defects in production, and achieve a decorative effect like silk satin, which is mainly used in stainless steel, aluminum, copper, iron and other metal products. According to the grain effect produced by wire drawing, there are mainly straight grain, chaotic grain, thread, corrugated and spiral weave. Straight wire drawing refers to the method of mechanical friction on the surface of the aluminum plate to process the straight line line, which has the dual function of brushing off the surface scratches of the aluminum plate and decorating the surface of the aluminum plate, including continuous silk pattern and intermittent silk pattern. Messy wire drawing is a kind of irregular, no obvious texture matte wire pattern obtained by moving the aluminum plate forward and backward and left and right under the high-speed copper wire brush, which has high requirements for the surface of aluminum or aluminum alloy plates. On home appliance panels, delicate straight grain drawing is commonly used, and by adjusting the mesh and running speed of the belt of the wire drawing machine, a uniform fine straight grain is drawn to improve the texture and grade of the product.

3. Etching: Etching is a process that uses chemical solutions or electrochemical methods to dissolve and remove unwanted parts from a metal surface, thereby creating the desired patterns, text, or shapes on the metal. In printed circuit board manufacturing, etching can precisely remove unwanted copper foil to form complex circuit patterns, meeting the high-precision circuit layout requirements of electronic devices. It offers extremely high precision, capable of producing fine lines and intricate patterns. Some delicate designs on metal crafts are achieved through etching, giving them high artistic value. Based on the etching principle and the reagents used, it can be divided into chemical etching and electrolytic etching. Chemical etching utilizes the dissolving action of chemical solutions on metals, while electrolytic etching dissolves metal through an electrolysis reaction at the anode. In practical applications, the appropriate etching method should be chosen based on the type of metal, required etching precision, and production costs. When making metal badges, chemical etching can be used to produce delicate patterns and clear text.

4. Laser Engraving (Laser Etching): Laser engraving is based on CNC technology, using a laser as the processing tool. By directing the laser beam onto the metal surface, the material instantly melts and vaporizes, achieving the engraving effect. It features high precision, with processing accuracy reaching 0.02mm, allowing for extremely fine pattern and text engraving. On the casings of electronic products, brand logos, model numbers, and other information are often engraved via laser engraving, appearing clear and refined. Since laser engraving is a non-contact process, it does not exert mechanical pressure or stress on the material, leaves no "cut marks," and does not deform the material, making it especially suitable for processing precision parts or products that require high surface quality. Additionally, laser engraving is fast and can perform high-speed engraving immediately based on computer-generated designs. For small-batch processing, laser engraving is more suitable, cost-effective, and not limited by production quantity. In industrial production, laser engraving can also be used to mark traceability codes on products, facilitating quality tracking and management.

5. Water Transfer Printing: Water transfer printing is a surface decoration technique that transfers patterns onto an object through a water medium. The process principle involves first printing the pattern on a water-soluble film, then placing the film in water, where the pattern dissolves and spreads out. The metal item to be treated is then immersed in the water, and the pattern transfers onto the metal surface. Finally, post-processing steps such as drying and curing ensure the pattern adheres firmly to the metal surface. Its biggest advantage is the ability to decorate surfaces with complex shapes; whether flat or curved, pattern transfer can be easily achieved. In automotive interiors, such as dashboards and door panels with irregular shapes, water transfer printing can be used to create high-end visual effects like wood or carbon fiber finishes, enhancing the overall aesthetic and perceived quality of the vehicle. Water transfer printing is relatively low-cost, suitable for large-scale production, and the resulting product patterns are delicate and vibrant, adding a unique visual appeal. In the 3C product field, devices such as phones and tablets can achieve distinctive appearances through water transfer printing, meeting consumers' demand for personalized designs. Depending on the transfer method, water transfer printing can be divided into water decal printing and water coating transfer printing. Water decal printing is mainly used for transferring patterns onto flat or simple curved surfaces, while water coating transfer printing is more suitable for decorating complex curved surfaces.

Synergistic application of metal processing and surface treatment In actual industrial design, metal processing methods and surface treatment processes do not exist in isolation, but cooperate and synergize with each other to jointly meet the needs of products in terms of function, appearance and cost. Take Apple's MacBook series of laptops as an example, its body is made of aluminum alloy, and during the metalworking stage, it uses precise CNC (computer numerical control) cutting technology. Through CNC machining, aluminum alloy materials can be accurately processed into complex shapes, ensuring the thin and light design of the fuselage and high-precision structural dimensions, such as the MacBook Air is only 4mm at its thinnest point, which benefits from the high precision and flexibility of CNC machining, achieving fine carving of metal materials. In the surface treatment process, the anodizing process is adopted, which not only gives the body a unique color and texture, but also improves the corrosion resistance and wear resistance of aluminum alloys, meeting consumers' dual needs for product appearance and durability. This synergistic application of metalworking and surface treatment has made the MacBook series highly recognizable and well-known in the market, and has become a classic case in the field of industrial design. Another example is the automobile wheel, which usually uses the forging process in metal processing, which can make the internal structure of the metal denser, improve the strength and toughness of the wheel hub, and meet the strict requirements of the car for the performance of the wheel hub at high speed and complex road conditions. The surface treatment adopts a variety of processes according to different market positioning and customer needs. For wheels that pursue sportiness and personalization, metal drawing may be used to create a unique texture effect and enhance the visual impact of the wheels; For the wheels of models that pursue a sense of luxury, the electroplating process will be used to plate chrome and other metals to make the surface of the wheels appear mirror-like and enhance the sense of grade of the vehicle. In terms of cost control, for the wheels of some low-end models, relatively low-cost surface treatment processes such as painting may be used to reduce production costs and improve the market competitiveness of products under the premise of ensuring a certain degree of aesthetics. In the field of medical devices, the manufacturing of surgical instruments requires high-precision metalworking and special surface treatments. Taking scalpels as an example, in the metal processing process, precision grinding and other processes are used to ensure the sharpness and dimensional accuracy of the blade to meet the precise requirements for cutting operations during surgery. The surface treatment adopts passivation treatment, forming a dense oxide film on the metal surface, improving the corrosion resistance of the scalpel, preventing rust during use and disinfection, and the passivation treatment can also reduce the adhesion of bacteria on the surface, reduce the risk of infection, and ensure the safety of surgery.

From these real-world cases, it is evident that the collaborative application of metal processing and surface treatment is an integrated engineering process. During the design phase, designers need to fully consider the product's functional requirements, aesthetic requirements, and cost budget, and select the appropriate metal materials and processing techniques. In the production process, metal processing determines the basic shape and structure of the product, providing the foundation for surface treatment; at the same time, surface treatment further enhances the product's performance and appearance based on the metal processing. Both are indispensable. Only by achieving an organic synergy between metal processing and surface treatment can high-quality products be manufactured that meet functional requirements, have a good appearance, and maintain reasonable costs, thereby gaining a competitive advantage in the market.Industry Trends and Outlook

Industry Trends and Outlook
With the rapid development of technology and the continuous changes in social demands, metal processing and surface treatment technologies are evolving in multiple directions. These trends will profoundly influence the future of industrial design.

In terms of new materials, novel metal materials such as metal matrix composites and nanometal materials are emerging one after another. Metal matrix composites combine the advantages of metals and other materials, featuring high strength, low density, and high thermal conductivity. They are expected to find broader applications in fields requiring extremely high material performance, such as aerospace and automotive industries. This will drive continuous innovation in metal processing techniques to meet the processing needs of new materials. Due to their unique nanoscale effects, nanometal materials exhibit excellent mechanical, electrical, and optical properties, holding great potential for applications in electronic devices, sensors, and other areas. Their surface treatments require entirely new technologies and methods to fully exploit the characteristics of nanomaterials.

The development of new processes is also notable. The application of 3D printing in metal processing is gradually maturing, enabling the rapid manufacturing of complex structures without molds. This greatly shortens product development cycles and manufacturing costs, providing greater creative space for industrial design. For example, in the medical device field, 3D printing allows for the customization of personalized metal implants. Micro- and nano-processing technologies can achieve precise processing of metals at a microscopic scale, producing micro- and nano-structures with special functions, such as metal components in microelectromechanical systems (MEMS). This will drive industrial design towards miniaturization and refinement.

Increasingly stringent environmental requirements are an unavoidable trend in the metal processing and surface treatment industry. Traditional metal processing and surface treatment processes often generate large amounts of wastewater, exhaust gases, and waste residues, causing serious environmental pollution. In the future, the concept of green manufacturing will permeate the entire industry. Companies will need to adopt more environmentally friendly processing methods and surface treatment technologies to reduce pollutant emissions. In surface treatment, eco-friendly coatings such as water-based and powder coatings will gradually replace traditional solvent-based coatings to lower volatile organic compound (VOC) emissions. In metal processing, there will also be a greater emphasis on resource recycling, improving material utilization, and achieving sustainable development.

These development trends have multifaceted impacts on industrial design. New materials and processes bring more possibilities to industrial design, allowing designers to break through the limitations of traditional materials and techniques to create more unique and high-performance products. Environmental requirements prompt designers to pay greater attention to the product lifecycle in the design process, considering the impact on the environment from material selection and manufacturing processes to product use and disposal, thereby driving industrial design toward greener practices. With technological advancements, the intelligence level in metal processing and surface treatment continues to increase, which also requires designers to possess higher digital design capabilities to better collaborate with intelligent production systems. Metal processing and surface treatment, as essential supports for industrial design, will develop in tandem with industrial design, mutually promoting progress and helping create better living and working environments.