Magnesium/titanium composite plate with large thickness ratios and gradient heterothermal rolling bonding method

A preparation method of a magnesium/titanium composite plate, comprising following steps:

• assembling blanks according to a sequence of a titanium strip, a transition layer foil and a magnesium alloy plate to obtain a composite blank;
• carrying out an induction heating treatment on one side of the titanium strip of the composite blank, and then rolling, and carrying out a heat treatment on a composite plate blank after rolling to obtain the magnesium/titanium composite plate;
• a thickness ratio of the magnesium alloy plate to the titanium strip is greater than or equal to 20:1;
• the titanium strip, the transition layer foil and the magnesium alloy plate are respectively subjected to an annealing treatment before the assembling, specifically, the titanium strip is held at 900-1000° C. for 60-90 min, the transition layer foil is held at 300-400° C. for 5-15 min, and the magnesium alloy plate is held at 300-400° C. for 30-60 min;
• after the annealing treatment, the titanium strip, transition layer foil and magnesium alloy plate are further subjected to a step of surface treatment to remove oxide layers;
• the transition layer foil is aluminum foil, zinc foil or aluminum-zinc alloy foil;
• the induction heating treatment specifically comprises:
• placing an induction heating coil on one side of the titanium strip of the composite blank to make the induction heating coil parallel to the composite blank, adjusting a distance between the induction heating coil and the composite blank to be 3-10 mm, and setting a heating temperature of heating the composite blank to be 400-600° C. for 15-150 s;
• a rolling reduction is 15-20% and a rolling speed is 0.5-1.0 m/s;
• a heterothermal rolling device for the preparation method of the magnesium/titanium composite plate comprises a guide rail support, two sides of the guide rail support are fixedly connected with a two-roll mill, a coil lifting device is fixedly connected to a feeding side of the two-roll mill and a top surface of one end of the guide rail support, the guide rail support is located between bottom ends of the two-roll mill, and the feeding side of the two-roll mill is correspondingly arranged with a discharging end of the coil lifting device.