Titanium as a precious metal, titanium and its alloys in the production of printed circuit board is widely used, such as titanium tanks, mainly used for multilayer inner black / brown treatment, multilayer plastic residue in addition to swelling, in addition to plastic tanks ( Sometimes alkaline chemical addition tank also apply to copper, stainless steel, but more than 316); electroplating anode titanium basket, such as Tong Gang, nickel cylinder, using solder balls of tin cylinder (surface coating of ruthenium, rhodium-plated treatment); gold cylinder insoluble anode ( surface using platinum, ruthenium or rhodium-plated handle); heating pipe / device (sometimes as hot document); cooling pipe, and some of the equipment enclosure. Such a wide range of applications, we should be some understanding of their nature. Titanium as the metal, has three characteristics: 1. No rust; 2. Light weight, density of only 4.51; 3. High strength (tensile strength 28-160kgf/mm) has excellent mechanical properties and excellentspecific strength (strength / density ratio), titanium has excellent performance even more.
Titanium also has the following several advantages:
1. Temperature characteristics: high temperature, tensile strength and excellent resistance to creep resistance, maximum 300 degrees titanium, titanium alloy at 500 degrees still has the strength and stability;
2. Low-temperature characteristics: the absolute value, embrittlement does not occur, it has good resistance to fatigue and fracture toughness;
3. Fatigue toughness: But after welding heat-affected region has significantly decreased fatigue phenomenon;
4. Corrosion resistance, acid and alkali resistance: The corrosion resistance of titanium depends on the stability of the surface oxide film.
Welding of Titanium
Thai titanium at high temperatures will react with oxygen and other gases, causing hardening, resulting in lower ductility welded crevice, resulting in porosity, corrosion resistance decreased; so titanium welding by inert gas or vacuum protection; welding is easy to produce re-crystallization , in particular, β-titanium, resulting in crystallization of thick, leading to their decline in ductility; other titanium welding deformation of large, correction is difficult.
General welding method
TIG, MIG, resistance welding, plasma welding, beam welding, laser welding, etc., the need for stress relief after welding the annealed or solution and aging treatment, and even dual solution and aging treatment to improve their strength, toughness and fatigue strength.
Titanium surface treatment
1, enhanced corrosion resistance treatment: air oxidation and anodic oxidation; not only can improve the corrosion resistance, but also can prevent hydrogen embrittlement; in addition to platinum, palladium oxide / titanium oxide treatment;
2, improved wear resistance: high temperature (800-900 degrees) for nitriding, the surface hardness up to 700 or more; by welding, in argon gas with the desired amount of nitrogen or oxygen, so that the surface hardness can increase 2-3 times; by ion plating, so that on the surface of a layer of titanium nitride, the thickness of about 5 microns, the surface hardness as high as 16000-20000; chrome, etc.;
Through the above titanium and its alloys on the simple understanding, we will understand that titanium and its alloys in PCB some role in the use, maintenance and so on will be inspired; titanium metal is the third largest, after following the Mg future applications as a wide range of metal.
