The material selection for casing production should be combined with product functions (such as protection, heat dissipation, and lightweight), usage scenarios (such as industrial, consumer electronics, and medical), and cost budgets. Common materials are mainly divided into three categories: metal materials, plastic materials, and composite materials. Their specific characteristics and applicable scenarios are as follows:

I. Metal materials: Emphasis is placed on strength, heat dissipation and durability

Metal casings are widely used in scenarios that require high structural strength, good thermal conductivity, or industrial-grade protection. Common types include:

Aluminum alloys (such as 6061, 5052

Core features: Low density (about 2.7g/cm³), only 1/3 of that of steel, achieving lightweight. Corrosion-resistant (the surface can be enhanced through anodic oxidation); It has good thermal conductivity (about 160-200 W/(m · K)), making it suitable for devices that require heat dissipation, such as laptops, servers, and industrial controllers. Easy to process (can be die-cast, CNC milled, bent).

Applicable scenarios: Consumer electronics (A-side of laptops, middle frames of mobile phones), industrial equipment casings, automotive electronic components.

Stainless steel (such as 304, 316

Core features: Extremely strong corrosion resistance (316 is more resistant to acids and alkalis than 304, suitable for humid/chemical environments); High hardness, impact resistance, and rust prevention on the surface without additional coating. However, it has a high density (about 7.9g/cm³), is relatively heavy, and is difficult to process (requiring special cutting/welding equipment).

Applicable scenarios: Medical equipment (requiring sterility and corrosion resistance), outdoor equipment (such as surveillance cameras, charging piles), kitchen appliances (such as oven shells).

Cold-rolled steel plate (SPCC

Core features: Low cost, high strength, and easy to form through sheet metal stamping. However, it has poor corrosion resistance and must be treated for rust prevention by spraying (such as powder coating, electrophoresis) or galvanizing. It is heavier than aluminium alloy and has average thermal conductivity (about 50 W/(m · K)).

Applicable scenarios: Low-cost industrial chassis (such as distribution boxes, server cabinets), household appliances (such as washing machine shells).

Magnesium alloy

Core features: Lighter than aluminum alloy (density approximately 1.8g/cm³), thermal conductivity close to that of aluminum alloy; However, it has poor corrosion resistance (surface treatment is required), high cost and complex processing technology (mostly die-casting).

Applicable scenarios: High-end lightweight devices (such as ultra-thin laptops, drone bodies).

Ii. Plastic Materials: Emphasis on lightweight, easy molding and cost control

Plastic casings account for the highest proportion in consumer electronics and small household appliances. Their advantages lie in the fact that they can be integrally molded into complex structures (such as clips and hollowed-out parts), and their cost is lower than that of metals. Common types include:

ABS (Acrylonitrile-butadiene-styrene Copolymer

Core features: Good comprehensive performance - impact resistance (still tough at low temperatures), easy to process (can be electroplated or sprayed after injection molding), moderate cost; However, its high-temperature resistance is limited (with a heat distortion temperature of approximately 90-110℃), and its weather resistance is poor (it is prone to aging after long-term outdoor use).

Applicable scenarios: Consumer electronics shells (such as routers, keyboards, printers), small household appliances (such as the outer pot of rice cookers).

PC (Polycarbonate

Core features: High transparency (can replace glass, such as "bulletproof plastic"); The impact strength is extremely high (2 to 3 times that of ABS); High-temperature resistant (heat distortion temperature approximately 120-140℃); However, it is prone to scratches (the surface needs to be treated with a coating), and has poor processing fluidity (complex structures require optimized molds).

Applicable scenarios: Transparent/semi-transparent shells (such as LED lamp covers, front frames of monitors), equipment that requires impact resistance (such as children's toys, industrial instrument panels).

PC/ABS alloy

Core features: Combining the high-temperature resistance and impact resistance of PC with the easy processing and low cost of ABS, the heat distortion temperature has been raised to 110-130℃, and its impact resistance is superior to pure ABS. It is currently the "mainstream choice" in consumer electronics.

Applicable scenarios: Mobile phone casings (especially mid-to-high-end models), laptop back covers, automotive interior parts.

PP (polypropylene

Core features: Low density (about 0.9g/cm³, one of the lightest plastics); Chemical corrosion resistance (acid and alkali resistance, oil stain resistance); Good toughness and foldable (such as "hundred-fold rubber"); However, it has poor heat resistance (with a heat distortion temperature of approximately 60-80℃) and weak surface adhesion (difficult to spray).

Applicable scenarios: Lightweight shells (such as the bases of small household appliances, storage boxes), and equipment that requires oil resistance (such as the filter frames of range hoods).

PA (Nylon, such as PA6, PA66

Core features: High strength, high toughness, and wear resistance (suitable for sliding parts); However, it has a high water absorption rate (prone to deformation due to moisture), and glass fiber reinforcement needs to be added (such as PA6+30% glass fiber to enhance strength and high-temperature resistance).

Applicable scenarios: Industrial equipment casings (requiring wear resistance and impact resistance), automotive electronic components (such as sensor casings).

Iii. Composite Materials: Focusing on special functional requirements

Composite materials are composed of two or more materials and are used to meet requirements that cannot be achieved by a single material (such as high strength + lightweight, insulation + high-temperature resistance) :

Glass fiber reinforced plastic (GFRP, commonly known as "glass steel"

Core features: With resin (such as epoxy resin, unsaturated resin) as the matrix and glass fiber as the reinforcing layer; High strength (close to metal) and light weight (density about 1.8-2.0g/cm³); Strong corrosion resistance and good insulation; However, the processing cycle is long (mostly hand lay-up/molding), and the surface flatness is poor.

Applicable scenarios: Large outdoor equipment (such as wind turbine nacelles, communication base station enclosures), corrosion-resistant equipment (such as chemical pipeline shells).

Carbon fiber reinforced plastic (CFRP

Core features: Its strength is five times that of steel, and its weight is only one quarter of that of steel. Good thermal conductivity and fatigue resistance; However, the cost is extremely high (10 to 20 times that of aluminum alloy), and the processing difficulty is great (requiring special molds and cutting equipment).

Applicable scenarios: High-end fields (such as aerospace equipment shells, racing car bodies, high-end unmanned aerial vehicle racks).

Flame-retardant plastics (such as flame-retardant ABS, flame-retardant PC

Core features: Flame retardants (such as brominated and halogen-free flame retardants) are added to the base plastic to achieve UL94 V0 level (extinguishes within 10 seconds of vertical burning without dripping) and other flame retardant standards; Meet the safety requirements of electronic devices (prevent short circuits and fires).

Applicable scenarios: Power adapter housings, server cases, medical equipment (fire protection certification required).

Summary: Core considerations for material selection

Functional requirements: Aluminum alloy/magnesium alloy is preferred for heat dissipation. For protection, stainless steel/GFRP is preferred. For lightweighting, plastic/magnesium alloy is preferred. For transparency, PC is preferred.

Cost budget: Choose cold-rolled steel plate/PP/ABS for low cost. For mid-to-high-end products, choose aluminum alloy/PC/ABS alloy. For high-end products, choose carbon fiber/magnesium alloy.

Processing technology: For complex structures, injection molded plastics (such as ABS, PC) are preferred. Simple planar structures can be made of sheet metal (such as cold-rolled steel plates, aluminum alloys).