Today, the editor will tell you about the genealogy and material knowledge of metal furniture.
The components of metal furniture are mainly made of metal, and some metal furniture also uses auxiliary materials such as wood, software, and plastic. Metals mainly include two categories: ferrous metals and non-ferrous metals. Because metal resources are relatively abundant, have good performance, and have many excellent modeling characteristics, they are also widely used in the field of furniture.
The surface of metal materials has good reflective ability, opacity and metallic luster, and can show the unique color of the metal itself, such as silver and aluminum, gray-white iron, orange-yellow copper, etc. It has excellent mechanical properties, such as high melting point, strength, stiffness and toughness. It has excellent processing properties, including plastic formability, castability, cutting processing and welding properties. The surface has good craftsmanship. Various decorative techniques can be used on the metal surface to obtain the ideal texture. For example, cutting and finishing can be used to obtain different texture effects; the mirror effect of inscription plating and polishing can be obtained. It gives people a luxurious feeling; the surface of the surface after plating sandblasting has a particle texture, producing a natural, mild and suppressed off-white color; coating, electroplating, and metal itching are performed on the metal surface. Available in various colors.
Currently, the materials commonly used in the manufacture of this tool mainly include steel, cast iron, copper alloy, aluminum alloy, etc.
Steel
Steel is an iron-carbon alloy with a carbon content between 0.02% and 2.11%. Steel also contains elements such as silicon, manganese, sulfur, and phosphorus. According to its chemical composition, it can be divided into carbon steel and alloy steel.
carbon steel
Also known as carbon steel, usually as the carbon content increases, the strength and hardness of the steel increase, and the plasticity, toughness and weldability decrease.
It can also be divided into three categories according to carbon content:
Low carbon steel: The carbon content is less than 0.25%. It has low strength, high plasticity, high toughness and good processability and weldability. It is suitable for manufacturing parts and structural parts with complex shapes and requiring welding.
Medium carbon steel: Carbon content is 025%~06%. It has certain strength, plasticity and moderate toughness. It has good comprehensive mechanical properties after heat treatment and is mostly used to manufacture gears, bearings and other mechanical parts that require strong toughness.
High carbon steel: with a carbon content of more than 0.6%, high strength and hardness, good wear resistance, low plasticity and toughness, it is mainly used to manufacture tools, cutting tools, springs and wear-resistant parts.
alloy steel
Steel based on carbon steel with an appropriate amount of one or several alloying elements added has higher comprehensive mechanical properties and some special physical and chemical properties. Alloy steel is divided into low alloy steel (total content less than 5%), medium alloy steel (total content 5%~10%), and high alloy steel (total content more than 10%) according to the total content of alloy elements. The base materials of steel mainly include strip steel (narrow strip steel with a length below 600mm and wide band steel with a length above 600mm) and steel plate. The former is processed into various types of pipes for bending and forming; the latter is processed into strips and block sheets, according to the structure. Stamping molding is required.
Most of the pipes used in metal furniture are high-frequency welded pipes, which are high-strength, elastic, and easy to bend, which is beneficial to shape design and easy to join with other materials. After the surface is plated and painted, it has various colors and beautiful appearance, and is often used as a supporting frame. The common ones are round tubes, and the more popular ones are square tubes, rectangular tubes, semi-elliptical tubes, rhombus tubes, shuttle tubes, fan-shaped tubes, triangular tubes, edge tubes and other special-shaped tubes. The strip steel used for pipes should comply with relevant national standards. The thickness of steel pipes using high-frequency welding is generally 1~1.5mm, and the outer diameters are Φ 13, Φ 14, Φ 16, Φ 18, Φ 19, Φ 20, Φ 22, Φ 25, Φ 28, Φ 32, Φ 36 (Unit: mm) and other specifications, commonly used ones are Φ 14, Φ 19, Φ 22, Φ 25, Φ 32, Φ36 (unit: mm). Increasing diameters facilitate fitting of pipes on furniture structures. The thickness of commonly used plates for metal furniture is 0.8~3mm. All plates used for warping or anti-extension should comply with the relevant technical conditions of national standards for ordinary carbon structural steel and low alloy structural steel thin steel plates and cold-rolled thin steel plates for deep drawing. .
In the production of metal furniture, steel wire mesh is used to make various bed bends and folding bed bases. The steel wire mesh used for furniture generally uses high-quality carbon steel above 45 steel, such as 45Mn, 65Mn, etc. The diameter of the steel wire is generally Φ0.8mm; the surface of the galvanized steel wire is woven using a mesh weaving machine, and the steel wires are interlaced with each other in a spiral shape. The mesh surface has a certain degree of flexibility; it is finally made by carding according to the required format size. In addition, furniture components can use low-alloy high-strength steel, such as 16Mn, which is a small amount of alloying element Mn added to low-carbon steel to make it have significant strength on the basis of good weldability, good toughness and plasticity. Carbon steel with a higher carbon content can reduce the weight of the furniture structure and save steel while ensuring strength.
cast iron
Cast iron is an iron-carbon alloy with a carbon content of 2.11% to 4.0%. It has a low melting point, good casting performance, cutting performance, wear resistance and vibration damping properties. The production process is simple and the cost is low. It can be used to manufacture various parts with complex structures and shapes. Commonly used cast iron materials include gray cast iron, malleable iron and ductile iron. It is mostly used in the production of certain parts of furniture, such as table legs, bases and other parts that bear pressure and require high stability.
copper alloy
Brass is a copper alloy with zinc as the sole or main alloying element. Yellow steel can be divided into pressure processed brass and cast brass. Brass has excellent deformation ability and aviation resistance, has a similar golden color, and is often used to make decorative parts for furniture. Buddha-made brass can be used to produce artistic furniture or furniture decoration pieces through pressing and other processes. The Sn content of tin bronze is generally 3% to 14%. Tin bronze containing less than 7% Sn has good plasticity and is suitable for pressure processing: tin bronze containing more than 10% Sn has low plasticity and high strength. , can be used for casting. Tin bronze has a low casting shrinkage and is suitable for casting castings with complex shapes and high dimensional accuracy requirements; tin bronze also has good corrosion resistance. Through casting, simple and elegant shapes can be obtained, which can be used in the production of beds.
Aluminum alloy
Aluminum has excellent properties. The density of pure aluminum is small, about 2.7g/cm3, which is equivalent to one-third of copper. It is a light alloy. Melting point 600C. After crystallization, aluminum has a face-centered cubic lattice, has high plasticity, and can be subjected to various plastic processing. Pure aluminum is silvery white. Aluminum has a high affinity with oxygen and can form a dense oxide film of aluminum trioxide, which isolates the air and prevents further oxidation. Therefore, it has good oxygen resistance in the atmosphere. Aluminum alloy is an ideal light metal material for making metal furniture. The furniture made is light, strong, easy to carry, and beautiful in color. Commonly used aluminum alloys include forged aluminum, rust-proof aluminum, hard aluminum, super-hard aluminum, special aluminum, etc. When selecting materials, it is necessary to select materials or alloys that can withstand heat treatment and have good corrosion resistance and cutting properties according to the furniture design requirements to prevent cold cracks and hot cracks from occurring during the production process. Aluminum alloy furniture is generally made of AI-Mg-Si alloy materials, which have medium strength, high corrosion resistance, no tendency of stress corrosion cracking, and good welding performance. Its material types include pipes, plates, profiles, strips, rods, wires, etc. The cross-sections of aluminum alloy pipes used for making furniture can be rolled into a variety of shapes according to usage, structure, connection and other requirements, and can be designed and made into ideal outer contours
Joining methods and structures of metal furniture
How to join metal furniture
welding
It can be divided into three categories: fusion welding, pressure welding and fiber welding. Furniture parts are often joined by gas welding and arc welding in fusion welding. It has good firmness and stability and is mainly used for parts subject to shear force and heavy load.
riveting
Mainly used for parts that are not suitable for welding, such as light metal materials. This connection method allows the parts to be surface treated before assembly, which brings convenience to processing. Its strength depends on the riveting material and the form of the willow joint. Because the riveting material has been physically deformed, it is difficult to restore and reuse it. Therefore, the strength of riveting is second only to welding, and it is also a fixed connection. The riveting method has lower material requirements, and many materials are available. This connection can also be used between different materials, but it requires strong external force to process.
Bolt and screw connections
The connection method of bolts can also be regarded as a variation of riveting. In addition to the characteristics of riveting, the biggest feature of bolts is that they can be used multiple times to realize the disassembly and assembly of components. In addition, it reduces the requirements for the connection process, and the connection can be implemented as long as there are generally small or manual tools.
Plug
Plug-in connection is to connect two or more parts together through plug connectors. Interference fits are often used between plug connectors and parts. Pins are also a general-purpose connector, mainly used for parts that are not subject to stress or have low stress, to position and assist in connection. The diameter of the pin can be appropriately determined according to the location and material used.
seam joint
Often used to connect thin metal sheets.
