JPS6040687A - Brazing filler metal of active metal - Google Patents

Abstract

PURPOSE:To decrease m.p. and to provide a brazing filler metal suitable for joining of a metal and ceramics by forming said brazing filler metal of the compsn. consisting of a specific amt. of >=1 kind of Cu and Ni, >=1 kind of Ti and Zr and a rare earth element. CONSTITUTION:A brazing filler metal of active metal is composed, by atomic %, of 10-80>=1 kind of Cu and Ni, 15-80>=1 kind of Ti and Zr and <5 rare earth element. Preferably 5-70>=1 kind among La, Ce and Pr is added as the rare earth element. The melt consisting of the above-mentioned compsn. is prepd. and the melt thereof is ejected onto a quick cooling drum under high speed rotation to cool quickly, by which the brazing filler metal of active metal is manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to active metal brazes containing rare earth elements.

[Technical background of the invention and its problems]

Metals and ceramics have different atomic bonding states, so the chemical properties such as chemical reactivity and physical properties such as thermal expansion coefficient and electrical conductivity of metals and ceramics are
They are very different. Therefore, various methods have been studied to properly weld the two parts and to perform highly reliable metallurgical joining.

Brazing does not change the base material. This method does not require large amounts of pressure and is easy to operate, making it an important joining method for joining metals and ceramics. Here, there is a brazing material that contains active metals, which is known as a brazing material that joins metals and ceramics.

The active metals are elements of the Iyb group in the synchronous table, such as Ti and Zr, and both are known to be effective in joining metals and ceramics. In particular, active metals have a melting point of high << Tt 1720℃, Zr 1860℃.
Although it is not suitable as a normal brazing filler metal as it is, in alloys with transition metals such as CuNi and Fe, the melting point is lowered by several hundred degrees Celsius in the eutectic composition region, for example, the lowest Tl-Cu alloy. It becomes 872℃. Focusing on this phenomenon, we have introduced active metals at the joints between transition metal base materials and ceramic base materials, or interposed both active metals and transition metals at the joints between ceramic and ceramic base materials. A patent (US PaT 2,857,663) discloses a method for forming alloys and performing bonding. Another possibility is to use an alloy of an active metal and a transition metal as a brazing material to join metals and ceramics, but alloys of active metals and transition metals are brittle and foil-like in many composition ranges. Since it is difficult to form a material into a desired shape, a waxwork made by forming the alloy into a thin plate with an amorphous structure using a method called melt spinning was developed and patented (Japanese Unexamined Patent Publication No. 56-163093 ) is disclosed.

These brazing materials satisfied many uses. However, as mentioned above (2. Metals and ceramics)
There are many different thermal expansion coefficients, especially when bonding combinations such as ceramic and Cu, which are often required in electronic parts, for example, Si and N4 ceramics have a thermal expansion coefficient of about 2.5XIO"-"/K, Also AJN
is approximately 4X10-'/, while Cu is approximately 17xl
O'/, and the two are very different. Therefore, when joining metals and ceramics that have significantly different coefficients of thermal expansion, stress often occurs due to the difference in thermal expansion between the two phases due to heating (secondarily, a ceramic rack is generated, causing a problem. As the temperature increases as the temperature increases, the bonding temperature between metal and ceramic decreases.Therefore, it is desired to develop a brazing filler metal with a low melting point that is suitable for bonding metal and ceramic.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an active metal brazing material which improves the above-mentioned problems, has a lower melting point, and is suitable for joining metals and ceramics.

[Summary of the invention]

In the course of intensive research to improve the above-mentioned problems, the inventors of the present invention discovered that by further adding C: a rare earth element to an alloy of a transition metal and an active metal, the melting point of the alloy was lowered by C-. The present invention was achieved by discovering a scale that can be used as a brazing material that can bond metals and ceramics well due to the effects of active metals.

That is, the present invention utilizes Cu and Ni, which form an alloy having a particularly low melting point among alloys of transition metals and active metals.
It is characterized by adding rare earth elements such as La, Ce, and Pr to the alloy obtained by combining the alloy with Ti or Zr.

In the present invention, transition metals and rare earth elements (especially Cu-C
In the eutectic composition region, the melting points of alloys of
C, 453°C, and has a low melting point of 500°C or less. Therefore, it is important to further lower the melting point of the alloy by adding these rare earth elements to the alloy of the active metal and transition metal. As the amount of rare earth elements added increases, the effect of lowering the melting point of the alloy becomes greater. Addition of rare earth elements not only lowers the melting point of the alloy, but also rare earth elements have a strong affinity with oxygen, and when joining oxide ceramics, the addition of a small amount of rare earth elements has a wedging effect and Various mechanisms such as improving chemical bonding with the base material can be expected to suppress the peeling of the oxide film.

Furthermore, when the amount of rare earth elements added is large, there is a high probability that compounds such as rare earth element oxides will be formed at the joint, which causes a phenomenon in which the joint strength between metal and ceramic is weakened. At the same time, it can be expected to have the effect of alleviating thermal stress generated during bonding.

If the amount of the rare earth element is less than 5 at %, the effect of lowering the melting point will be small, and if it exceeds 70 at %, oxidation of the brazing material may occur.

In the present invention (2), the ceramics to be bonded include nitrides (AJN, 8i, N, etc.) and carbides (SiC).
etc.) and various ceramics including oxides (A7.o3 etc.).

Further, the active metal brazing material of the present invention can also be manufactured by applying a commonly used molten metal quenching method. That is, it is manufactured by preparing a melt having the composition of the desired filler metal, and spouting the melt onto a rapidly rotating rapidly cooling drum. At this time, the cooling rate is set at least 10"T.
/5ff-rubbing is preferred. In this way,
A continuous foil provides a highly ductile active metal filler metal.

[Embodiments of the invention]

A brazing filler metal was prepared by adding 10 at.% of Ce to an active metal brazing filler metal containing 72 at.% of Cu and 128 at.% of T. While the melting point of the active metal brazing material was about 880°C, the melting point of the brazing material according to the example was about 830°C, which was 5.
A decrease in melting point of 0°C was confirmed.

Next, an active metal brazing material (thickness: 40 μm) according to the present invention was produced by a molten metal quenching method.

10 long angle, 2n thick AAN and 10 mm thick, 100μ thick
After cleaning and degreasing the joint surface of the oxygen-free copper with trichlene and acetone, the filler metal of the example was inserted into the joint and set in a hot press with a vacuum level of 2 x 10'' Torr. A pressure of 0. I Kp /- was applied from above and below between the materials, and high frequency heating was applied (the two-stranded joint was held at 850° C. for 10 minutes.

As a result of observing the cross section of the joint using an optical microscope, no voids or cracks were observed in the joint, indicating a good joint condition.

〔Effect of the invention〕

As described above, the present invention provides an active metal wax phase car that has a lower melting point and is suitable for joining metals and ceramics. asked.

Agent: Patent Attorney Noriyuki Chika (1 other person) PJ′r[ 0 shots clear person white Kane Makotokawa 1 the law of nature Odd 1

Claims (1)

[Claims] (10 to 80 atomic % of at least one of Cu and Ni,
15 to 80 at% of at least one of Ti and Zr and 5
Active metal wax containing atomic percent or more of rare earth elements. (2) Rare earth elements, 5 to 70 atomic % La, Ce. The active metal brazing material according to claim 1, which is at least one type of Pr.