Platinum metal metallurgical physical properties make it a spot weldability is poor

Platinum metal metallurgical physical properties make it a spot weldability is poor, platinum products at home and abroad to connect far more riveting process . Developed by the authors of this " single- cycle pulse key projection welding foil new technology" , as well as to achieve the two layers of platinum foil product no cushion welded directly in the trial production of some products can be indicated in the application . Introduced the new technology is the main process characteristics and   molybdenum alloys   mechanism . Product launch tube projection welding weld head surface topography x50 bump bonding design, direct spot platinum foil electrode and the workpiece surface will produce serious bonding process which destroys the normal spot . Domestic and international studies show that bonding is difficult to achieve with products direct spot one important reason . After use of  molybdenum screws  , the current can be in the dyeing of the bump and the internal heat increases the distance between the electrode surface , the temperature gradient along the thickness direction is easily formed . Meanwhile, the projection welding electrode end face than the large multi- spot welding , a significant increase of the contact area of ​​the electrode and the workpiece , reducing the welding electrode and the workpiece surface the heating intensity , which are effective in reducing the sticking of the electrode . Further , since the projection welding can reduce the energy input ( reduced welding current ) , reducing grain products grew , the key to improve the welding heat brittleness .