Metal material with thermodynamic anisotropy and a method of preparing the same

1. A metal material having thermodynamic anisotropy comprising:

an X-axis hardness of 160-180 HV, an X-axis thermal expansion coefficient of 5×10 −6 -100×10 −6 K −1 ;

a Y-axis hardness of 160-180 HV, a Y-axis thermal expansion coefficient of 5×10 −6 -100×10 −6 K −1 ; and

a Z-axis hardness of 180-250 HV, a Z-axis thermal expansion coefficient of 50×10 −6 -1000×10 −6 K −1 ,

wherein the metal material is prepared by a process that includes the following steps:

preparing an electroplating base solution that includes a copper sulfate solution having a divalent copper ion concentration of 40 g/L, a sulfuric acid solution having a sulfuric acid concentration of 120 g/L, and a hydrochloric acid having a chloride ion concentration of 50 ppm;

adding an organosulfate having a concentration of 4 mL/L, polyethylene glycol having a concentration of 15 ml/L, and a quaternary ammonium salt having a concentration of 35 mL/L to the electroplating base solution; and

conducting electroplating at a current density of 5 A/dm 2 for 40 minutes to obtain the metal material,

wherein the organosulfate is sodium lauryl sulfate, disodium 3,3-dithiobispropane-sulphonate, or 3, 3′-dithiobispropanesulfonic acid and the quaternary ammonium salt is

2. The metal material of claim 1 , wherein the metal material is selected from the group consisting of copper, tin, silver, nickel, chromium, cobalt, and an alloy thereof.

3. The metal material of claim 1 , wherein the X-axis hardness is 140-150 HV, the Y-axis hardness is 140-150 HV, and the Z-axis hardness is 190-220 HV.

4. The metal material of claim 1 , wherein the X-axis thermal expansion coefficient is 5×10 −6 -10×10 −6 K −1 , the Y-axis thermal expansion coefficient is 5×10 −6 -10×10 −6 K −1 , and the Z-axis thermal expansion coefficient is 80×10 −6 -120×10 −6 K −1 .