Mg alloy smartphone shell

 Advantages of magnesium alloy smartphone shells

Lightweight: The density of magnesium alloy is much lower than traditional metals such as steel and aluminum alloy, making smartphones lighter.

High strength: Magnesium alloys possess high tensile strength and yield strength, which can effectively resist external impact.

Good thermal conductivity: Magnesium alloys have excellent thermal conductivity, aiding in rapid heat dissipation from inside the smartphone.

Corrosion resistance: Properly treated magnesium alloy casings can resist various corrosive environments, prolonging the service life of the device.

Electromagnetic shielding: Magnesium alloy also provides a certain degree of electromagnetic shielding, reducing electromagnetic interference to the phone.

Large-scale applications of magnesium alloy in smartphones

Xiaomi Mi 11 Lite: In 2021, Xiaomi launched the Mi 11 Lite, the first mass-produced 5G smartphone with a magnesium alloy body. With a thickness of only 6.81 mm and a weight of 159 g, the model demonstrates the weight-reduction advantage of magnesium alloy.

Sharp Aquos Zero6: In the same year, Sharp released the Aquos Zero6, known as the world’s lightest 5G smartphone, weighing only 146 g. It features a magnesium alloy body and IP68-level dustproof and waterproof capabilities, showcasing the potential of magnesium alloy in lightweight and durable applications.

Microstructure and performance optimization of commonly used magnesium alloys

a. Common magnesium alloy grades and performance comparison

AZ31 (Mg-Al-Zn series): Tensile strength ≥240 MPa, elongation 12%, density 1.78 g/cm³, widely used in mid-range smartphone frames.

AZ91D (high aluminum content): Tensile strength increased to 280 MPa, elongation 7%, suitable for foldable phone hinge structures requiring higher strength.

Rare earth magnesium alloys (e.g., WE43): With the addition of Yttrium (Y) and Neodymium (Nd), creep resistance temperature is elevated to 250°C, potentially applicable in future smartphone shells.

b. Breakthroughs in manufacturing processes

Thixomolding® (semi-solid injection molding): Magnesium alloy granules are heated to the semi-solid state (580–620°C) and injected into molds at high speed. This process shortens molding cycle by 30%, with product porosity <0.1%.

3D printing (SLM): German company EOS developed magnesium alloy powder (Mg-Zn-Zr series). After selective laser melting, the tensile strength reaches 350 MPa. OPPO’s 2023 concept phone employed this technology to create a 0.3 mm ultra-thin honeycomb structured frame.

c. Surface treatment technologies 

Micro-arc oxidation (MAO): Generates a 10–30 μm ceramic layer through plasma discharge in electrolyte solution, with hardness up to HV 800. Sharp Aquos Zero6 uses this technology for corrosion and wear resistance.

Nano composite coating: A graphene/boron nitride composite layer is deposited on the magnesium alloy surface, raising the thermal conductivity to 220 W/(m·K). Enhances corrosion resistance, surface wear resistance, and introduces self-healing for surface abrasion defects.

Applications and challenges

Although magnesium alloy smartphone shells offer many advantages, their manufacturing cost is relatively high, and processing is technically demanding. Further breakthroughs in material properties and processing techniques, along with the successful development of new stainless magnesium alloys, will pave the way for broader applications.

Aikerly's Services 

Aikerly provides a large quantity of magnesium alloy granules for semi-solid injection molding processes, and also offers extrusion molding and CNC machining services for magnesium alloy smartphone frames. The company is also exploring the feasibility of producing magnesium alloy smartphone shells via hot stamping technology.