JPS60259306A - Composite tool and preparation thereof - Google Patents

Abstract

PURPOSE:To improve abrasion resistance and toughness by friction-welding a superhard alloy tip onto a steel supporting body larger than the tip through the metal or alloy having a high strength in a prescribed thickness. CONSTITUTION:A superhard alloy tip 1 is previously joined with a metal or alloy joint member 3 having a high strength such as Ni or Ni-alloy joint member in a thickness of 1mm. or less, and said tip 1 is formed integrally with a steel supporting body 2 through friction-welding. With such constitution, abrasion resistance and toughness can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a composite tool that is particularly excellent in wear resistance and toughness, and is inexpensive, and a method for manufacturing the same.

(b) Technical background Cemented carbide is known as an excellent tool material with high wear resistance and toughness, but compared to tool steel, it has the drawbacks of being expensive and brittle.

This invention aims to provide a composite tool that combines only the best features of cemented carbide and steel.

That is, it is a tool that is actually used, for example, in which only the cutting edge part is made of cemented carbide, and the rest is made of steel.

The most popular type of composite tool is one in which both are brazed together, and is used, for example, in drill end mills.

However, problems have been pointed out, such as insufficient brazing strength and inability to use at high temperatures.

(c) Disclosure of the invention In order to solve the problems of the above-mentioned conventional compound tools,
Up to now, various joining methods have been studied.

Friction welding is one of the methods being studied.

However, all of these are of the type in which a cemented carbide tip is directly joined to steel, which does not provide sufficient joint strength, so they have not been put into practical use much.

An object of the present invention is to provide a composite tool having high joint strength and high heat resistance of the joint, and a method for manufacturing the same.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

When joining a cemented carbide chip to a steel support with a large volume, a high-strength metal or alloy plate is sandwiched between the chip and the support as a joining member, and the chip, the support, or both are moved at high speed. Rotate.

At this time, frictional heat is generated between the chip and the high-strength metal or alloy, or between the high-strength metal or alloy and the support, and the high-strength metal or alloy softens and flows, so that it is distributed uniformly over the entire joint between the chip and the support. It is possible to join them.

Furthermore, it is possible to join a high-strength metal or alloy to the end face of the cemented carbide tip 1 as a joining member 3 in advance as shown in FIG. 1, and then friction weld this to the steel 2 as shown in FIG. More desirable.

The joining member 3 can be joined to the end of the chip 1 in advance by placing the powder-embossed body on the metal plate used as the joining member during sintering, or by changing the sintering atmosphere to bond the cemented carbide. Either by leaching the bound metal in the alloy to the surface, or once sintered,
Various methods can be considered, such as a method of bonding metal plates to be bonded members by heating them at high temperature under pressure.

Conventionally, attempts have been made to join cemented carbide and steel by friction welding, but there was no idea that using a joining member such as the one described above would work.

For this reason, the steel may not be completely bonded to the cemented carbide surface, or the friction welding conditions may be made stricter in an attempt to improve the bonding, resulting in increased heat generation and, as a result, thermal cracks may occur in the cemented carbide part. Was.

Suitable metals and alloys for joining the chip and steel are iron group metals or alloys containing these as main components. Among them, Momo or NL is used as a binder phase for the cemented carbide to be joined, and is preferred because it is unlikely to cause metallurgical defects that would reduce the joint strength during brooming.

In particular, when NL or NL gold alloy is used as a joining member, carbides such as WC and (W)C in the cemented carbide decompose during joining and react with the metal of the joining member, forming a harmful composite carbide phase. There is little chance of precipitation, and extremely high-strength bonding is possible.

The thickness of the high-strength metal bonding layer as a bonding member is preferably 1 mm or less. This is because if the thickness exceeds 1 mm, the abrasion resistance and strength of the high-strength metal bonding layer will deteriorate, which is undesirable.

The first application for which the composite tool of the present invention is used is a drill.

Drills that use cemented carbide only at the tip and are brazed to a steel shank are currently in considerable use, but they have problems such as insufficient strength and detachment when drilling deep holes or when processing high-strength materials. There is. The drill comprising the compound tool of the present invention is excellent in this respect and does not have any problems. In addition to drills, it is useful for various uses such as end mills, punches, and bits.

Hereinafter, this invention will be explained in detail with reference to Examples.

Example 1 A Ni plate with a thickness of 1 mm was bonded to the end face of a WC-5% sheet with a diameter of 10 mm and a length of 20 mm by heating it to 1320 DEG C. in a vacuum.

5KH9 types of round bars with a diameter of 10 mm and a length of 120 mm)
1.WC-5%Cofy7tr#forceiooom, 3
ooooa roll After rotating for 7 minutes, increase the pressure to 250
It was raised to 0 kg and then cooled.

In the joint, both the NL and the steel part were flowing, and the thickness of the NL remaining between the cemented carbide and the steel was 0.1 mm. After removing the debris generated by the flow, the shear strength of the joint was measured.

As a result, the composite tool of the present invention showed a value of 65-/-, significantly exceeding the value of 15 kg/- for the brazed tool.

Example 2 A chip with a diameter of 10 mm and a length of 10 mm is coated with a metal mainly composed of NL as a binder with a thickness of approximately 100 μm on the surface using TL C-TL N base metal. Obtained by sintering. This chip has a diameter of 10 m and a length of 100 mm.
It was joined to die steel. Then the pressure was 1100 ki, 25
After heating the chip for 1.5 seconds while rotating it at 00 rpm, the pressure was increased to 3000 kg, and then the rotation was stopped and cooled.

The shear strength of this joint was 60 kg/-.

Example 3 (MoW) c-1o% alloy, Cr3C210%N
Shigokin, T.

A N-20% Nj alloy chip was attached to a steel (SK-5) round bar. In this case, plates of NL, ω, and Fs with a thickness of 0.8 mm were prepared, and when performing friction welding, these plates were sandwiched between the tip and the 5K-5 gate and rotated.

The friction welding method was performed under the same conditions as in Example 2.

When we tried various combinations and measured their shear strength, we found that the worst case was 20klJ, and the best combination was 90klJ.
-Indicated the value of the accommodation.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams showing the configuration of a cemented carbide tip support and a joining member used to obtain a composite tool according to the present invention. 1...Cemented carbide chip 2...Support 3...Joining member patent applicant Sumitomo Electric Industries Co., Ltd. Agent Patent attorney Kazu 1) Showa 1 procedure manual (spontaneous) 1985 February 26, 1982 Patent Application No. 113707 2 Name of the invention Composite tool and its manufacturing method Address 5-15 Kitahama, Higashi-ku, Osaka Name (21
3) Column 6 of "Detailed Description of the Invention" in the specification of Sumitomo Electric Industries, Ltd., content of amendment as shown in the attached sheet, content of amendment 1, page 8 of the specification, lines 13-14, "Joined to die steel." Pressure 1100Kg, 25
At 00 rotations, the pressure was 1100Kg, 250
I corrected it to 0 revolutions/minute.

Claims (1)

[Claims] (1) A cemented carbide chip is friction welded to a steel support having a larger volume than the chip via a high-strength metal or alloy with a thickness of 1 mm or less. A compound tool featuring: (21 Cemented carbide is WC, (ratio, W)C, TiclTLN
The composite tool according to claim 11, characterized in that it is a sintered alloy containing any one of Cr5C2 as a main component. (3) The composite tool according to claim 1, wherein the high-strength metal or alloy is Ni, Co, or an alloy thereof. (4) A high-strength metal or alloy plate is sandwiched between the end face of the cemented carbide chip and the end face of steel having a larger volume than the chip, and the chip or the steel or both are moved at high speed. A method for manufacturing a composite tool, which comprises rotating the tool, heating it by friction with a high-strength metal or alloy, causing the high-strength metal or alloy to flow, and joining steel and chips. (5) Cemented carbide is WC, (ratio, W)C, TLClTL
5. The method for manufacturing a composite tool according to claim 4, wherein the composite tool is a sintered alloy containing either N or Cr3C2 as a main component. (6) The method for manufacturing a composite tool according to claim 4, wherein the high-strength metal or alloy is NL, Co, or an alloy thereof. (7'l) A high-strength metal or alloy is bonded to the end face of a cemented carbide tip in advance, and the tip, the support, or both are rotated at high speed to bond the high-strength metal or alloy to each other or the high-strength metal or alloy. A method for manufacturing a composite tool characterized by heating the alloy and cemented carbide by friction and flowing a high-strength metal or alloy to join the tip and steel. (8) The cemented carbide is WC, ( A method for manufacturing a composite tool according to claim 7, characterized in that the composite tool is a sintered alloy containing any one of C, TLC, πN, or CrJC2 as a main component. (9) High 8. The method for manufacturing a composite tool according to claim 7, wherein the strong metal or alloy is NL, Co, or an alloy thereof.