Titanium Brazing Alloys

Titanium brazing alloys are mainly of three types and based on titanium ((70Ti-15Cu-15Ni) or silver or aluminum. Titanium brazing alloys need temperatures nearby 1700° F, whereas the aluminum and silver-base alloys require 1100- 1250° F and 1650° F respectively. Titanium brazing alloys provide superior resistance to saline environments and atmospheric corrosion.

Titanium Brazing
Titanium is a very important but costly metal. Its use in a number of important areas makes it more valuable. Titanium is joined to itself or other metals through different brazing processes, such as resistance brazing, furnace brazing, and induction brazing in vacuum or in an argon atmosphere. However torch brazing can't be applied to titanium.

Common Types of Titanium Brazing Alloys

Composition of Titanium Brazing Alloys	Melting Range °F (°C)	Brazing Range °F (°C)
Ti-15Cu-15Ni	1655-1742 (902-950)	1800-1920 (980-1050)
Ti-15Cu-25Ni	1653-1679 (901-915)	1705-1760 (930-960)
Ti-24Zr-16Cu-16Ni-0.5Mo	1535-1560 (835-850)	1630-1690 (890-920)
Ti-20Zr-20Cu-20Ni	1555-1572 (848-856)	1560-1620 (870-900)

Titanium
Titanium is a transition metal having the symbol Ti and atomic number 22. It is a strong, light, lustrous, corrosion-resistant, with white-silvery-metallic color. It can be alloyed with a number of other elements such as iron, aluminum, molybdenum, etc to produce strong lightweight alloys. These alloys are used for aerospace (jet engines, missiles, and spacecraft), military, industrial process (chemicals and petro-chemicals, desalination plants, pulp and paper), in automotive sectors, etc.

Physical Properties
Phase		Solid
Melting Point		1941 K (1668 °C, 3034 °F)
Boiling Point		3560 K (3287 °C, 5949 °F)
Density (near r.t.)		4.506 g-cm-3
Liquid density at mp.		4.11 g-cm-3
Heat capacity at 25 °C		25.060 J-mol-1-K-1
Heat of fusion		14.15 KJ-mol-1

Chemical Properties
Phase		Solid
Oxidation States		2, 3, 4
Atomic Radius		140 pm
Electro-negativity		1.54 (Pauling scale)
Crystal Structure		Hexagonal
Ionization Energies		1st: 658.8 KJ/mol 2nd: 1309.8 KJ/mol 3rd: 2652.5 KJ/mol
Standard Atomic Weight		47.867 g/mol

Some Useful Properties of Titanium

• Titanium is a low-density element.
• It is nonmagnetic and possess good heat-transfer properties.
• It can be vastly strengthened by alloying and deformation processing.
• It shows high degree of immunity to attack by strong acids, minerals, and chlorides.
• Titanium and its alloys have higher melting points than those of steels.
• It is nontoxic and biologically compatible with human bones and tissues.
• It exhibit excellent corrosion resistance.