pressing nitrogen protection atmosphere sintering extruding and drawing but not limited to the operation and technological parameters of following embodiments 1 adopting chemical plating to cover a nickel coating on aquadag to reach 5 average content weight percentage of the aquadag and 95 average weight percentage of nickel this embodiment can be realize by following existing technology a firstly using concentrated nitric acid to perform surface modification of aquadag powder specific process putting 5 g aquadag powder into 20m1 concentrated nitric acid 40 holding temperature at 80 u00b0 c and providing backflow for 3 h filtering washing and drying for standby application b sensitizing treatment putting surface modified aquadag powder into 2 g l sncl 2 2h 2 o solution for sensitizing treatment for 10 minutes c putting well sensitized aquadag powder into 0 1 g l pdcl 2 solution stirring for 10 minutes filtering washing for standby application d putting well treated aquadag powder into nickel sulphate plating solution ultrasonic dispersion for 10 minutes then putting it into thermostatic bath plating for 30 minutes with stirring with temperature at 85 u00b0 c and ph of 5 6 after plating conduct washing and filtering until ph value is close to neutral preparing ni coated aquadag powder ni u2014 c through in situ reduction 2 further adopting the chemical plating to cover silver coating on nickel coated aquadag wherein afterwards an average percentage of.