Alloy 29-17, Alloy, Precision Alloy, Chinese Metal Supplier

Overview

Alloy 29-17 is a a vacuum melted nickel-iron-cobalt low expansion alloy containing approximately 29% nickel and 17% cobalt. Its chemical composition is controlled within narrow limits to assure precise uniform thermal expansion properties. Extensive quality controls are employed in the manufacture of this alloy to ensure uniform physical and mechanical properties for ease in deep drawing, coining, stamping and machining.

Characteristics

Alloy 29-17thermal expansion characteristics match those of borosilicate glasses and alumina type ceramics. It is manufactured to a close chemistry range, yielding repeatable properties which make it eminently suitable for glass-to-metal seals in mass production applications, or where reliability is of paramount importance.

Application

Alloy 29-17is anickel-iron-cobalt alloy which exhibit low expansion at room temperature. They have a coefficient of thermal expansion similar to that of glass. Therefore these types of alloys are used in many glass to metal and hermetic sealing applications.

Alloy 29-17 has been used for making hermetic seals with the harder Pyrex glasses and ceramic materials. This alloy has found wide use in application where high reliability is a necessity. In power tubes, x-ray tubes, lighting tubes, microwave tubes, vacuum tubes, transistors, diodes, photography flash bulbs and intergrated circuits such as flat pack, the dual-in-line package and optoelectronic component cases and bases. The alloy is also frequently used in the telecommunications, military and defense, aerospace and electronic industries.

Chemical Composition (wt%)

Material	Ni	Fe	Co	Mn	Si	C	Al	Mg
Alloy 29-17	28.5~29.5	balance	16.8~17.8	≤0.50	≤0.20	≤0.03	≤0.10	≤0.10
Material	Zr	Ti	Cr	P	S	Cu	Mo
Alloy 29-17	≤0.10	≤0.10	≤0.20	≤0.020	≤0.020	≤0.20	≤0.20

Al+Mg+Zr+Ti:≤0.20%

Typical Mechanical Properties of Alloy 29-17 (Soft annealed condition)

Temperature		Tensile strength		Yield strength (0.2% offset)		Elongation on 50mm (2 inch)	Reduction of area
°C	°F	MPa	ksi	MPa	ksi	%	%
20	68	520	75	340	49	42	72
100	212	430	62	260	38	42	72

Hardness

Annealed: 160 HV (83 HRB) max.

Full hard: 230 HV (97 HRB) min.

Heat Treatment

Alloy 29-17 is non-hardenable by heat treatment.

The alloy is normally used in the annealed condition, attained by heating, preferably in hydrogen or cracked ammonia, to 850-1000°C (1560-1830°F).

Decarburization to prepare for glass-to-metal sealing is usually carried out in an atmosphere of wet hydrogen at 900- 1050°C (1650-1920°F) for 1 hour. For seals requiring a metal oxide interface, the alloy can be oxidized by heating in air to temperatures in the 600-1000°C (1110-1830°F) range, depending on the thickness of oxide film required.

Product Forms

Form	Size range
Capillary tube	OD 0.08 ~ 6.0 mm WT 0.015 ~ 1.5 mm
Thin wall & Ultra thin wall seamless tube	OD6.0~80.0 mm WT 0.05~4.5 mm
Micro ID and heavythick wall seamless tube	OD3.0~50.0 mm ID0.30~5.0mm
Precision conic seamless tube	Bigger end: OD3.0 - 426.0mm Smaller end: OD2.5 - 346.0mm WT: 0.15 - 40.0mm
HP/UHP BA+ tube EP tube	OD 1.0 ~ 76 mm WT 0.10 ~ 10.0 mm
Small caliber precision seamless tube	OD6.0 ~89mm WT 0.50 ~9.0 mm
Profiled seamless tube	Build to drawing Build to specification
Bourdon tube	Y40, Y50, Y60, Y70, Y100, Y150