Composite metal shell and preparation method

The invention provides a composite metal shell, which comprises an aluminum alloy outer layer, and a zirconium-based alloy inner layer which is performed die-cast formation in the aluminum alloy outer layer. The invention also provides a method for preparing the composite metal shell, which comprises the following steps: 1) stamping the aluminum alloy base material or forging and stamping to a shell blank, placing the shell blank in a vacuum die cavity, and then locking the die; and 2) heating and fusing a zirconium-based amorphous alloy raw material under the vacuum condition to form a melt, then pressing the melt by a die casting machine through an extruder cylinder in a flow channel, filling in the die cavity in the die cavity under the temperature of 550 DEG C-650 DEG C until a zirconium-based amorphous alloy structure is formed, and then keeping the pressure for 15-25 seconds and demoulding to obtain the product. The preheating temperature of the die is 140-200 DEG C. The composite metal shell can form a