JPS583938A - Production of brass material - Google Patents

Abstract

PURPOSE:To obtain a brass material of small contact resistance formed with conductive layers of much copper contents on surfaces by heating the brass material to temp. higher than the b.p. of zinc in an atmosphere of nearly a vacuum thereby allowing the zinc to evaporate. CONSTITUTION:A brass material 1 which is made as a hoop material mounted on a rewinding drum 2 is removed of oil and water stuck thereon by a preheater 4, and enters a vacuum heating furnace 5 through chambers 7, 7. In the chambers, gaseous N2 is fed in order to prevent the inclusion of air through insertion holes 8 and the degree of vacuum is increased gradually in order to maintain the inside of the furnace 5 approximately in a vacuum. In the furnace 5, the material 1 is heated to temp. higher than the b. p. of zinc in approximately a vacuum state by heating chambers 6 to allow the zinc on the surfaces to evaporate, whereby conductive layers 12 of much copper content are formed. The material 1 is further subjected to rolling with a rolling mill 9 consisting of work rolls 10 and backup rolls 11, whereby the mechanical properties thereof are improved and the surfaces 1a roughened by the evaporation of zinc are made dense.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brass material with low contact resistance.The conventional method of this type is to plate brass to form a conductive layer of a good conductor to reduce contact resistance. There is.

However, as the device becomes larger, the productivity is also low, and the conductive layer is easily peeled off, so it is difficult to plate the hoop material and then bend it into parts.

This invention was made focusing on the above circumstances,
The purpose of the first invention is to provide a method for manufacturing a brass material that has a conductive layer with high conductivity without using other metal materials and has high productivity. The object of the present invention is to provide a method for manufacturing a brass material with high mechanical strength.

An embodiment of the first invention and the second invention will be described below based on FIGS. 1 to 3. Reference numeral 1 is a brass material made into a hoop material, and is attached to the rewinding drum 2. 3 is a winding drum. 4 is a preheater, which removes oil, moisture, etc. attached to the brass material 1 and dries the brass material 1. 5
is a vacuum heating furnace, which has a heating chamber 6 which obtains an almost vacuum atmosphere and heats the zinc above the boiling point at which it evaporates in that state, and a heating chamber 6 which has a degree of vacuum higher than that of the heating chamber in order to increase the degree of vacuum in this heating chamber B. A plurality of low chambers 7 are formed before and after the heating chamber B, and the degree of vacuum is gradually increased toward the heating chamber 6, thereby bringing the heating chamber 6 closer to a vacuum atmosphere. In addition, nitrogen gas is introduced into the heating chamber 6 to remove oxygen that enters through the insertion hole 8 of the brass material 1 and to bring it into a finely oxidized state. Reference numeral 9 denotes a rolling machine for roll rolling, which consists of a work roll 10 with a small diameter and a thick support roll 11 that applies pressure. Reference numeral 12 denotes a conductive layer with a high copper content, and after being dried by removing oil and moisture in a preheater 1, the layer is placed into a vacuum heating furnace 1 through an insertion hole 8, and the degree of vacuum is gradually increased in a chamber 7. Then, the heating chamber 6 is placed in a substantially vacuum state (for example, 10
'[Torr]). The brass material 1 stored in this state is heated. Zinc contained in the brass material 1 evaporates at a boiling point of 1180 ['K] under normal atmospheric pressure of 1 atmosphere, but as the temperature approaches a complete vacuum, the boiling point of evaporation decreases and it evaporates even at about 500 ['K]. It is something to do. Utilizing this property, zinc on the surface of the brass material 1 is evaporated to form a conductive layer 12 with a high copper content, as shown in FIG.

In this state, the electrical properties of the brass material 1 are improved by high-temperature heating, but the mechanical properties, that is, the strength, are reduced, so it is possible to roll it using the rolling machine 9 to improve the mechanical properties. . In addition, the surface 1a, which has become rough due to evaporation of zinc, can be made denser by rolling. In the case of a rod-shaped brass material 1, a rolling machine 9 for drawing is used. It is.

As shown in FIG. 3, the electric wire W is connected to a lock spring 16 made of stainless steel and having a lock piece 13 and a pressing piece 14.
In particular, when used as a material for the terminal plate 16 connecting the lock spring 1, the contact resistance with the electric wire W is almost as small as that of steel material, which prevents heat generation, and also prevents the lock spring 1.
5 and prevents current from flowing to the terminal plate 16. Furthermore, the disadvantage of brass material that it cracks due to stress corrosion can be prevented by forming a highly conductive layer 12 made of copper, which is less likely to cause corrosion, on the surface of the brass material.

As explained above, in this first invention, a brass material 1 is placed in a substantially vacuum atmosphere, heated in the atmosphere to a temperature higher than the boiling point of zinc to evaporate the zinc, and a conductive layer 12 having a high copper content is formed on the surface.
, it has a conductive layer 12 with high conductivity without using other metal materials, reduces contact resistance, prevents the occurrence of period cracking, and is significantly more productive than the dezincing method using acid. A method of manufacturing brass material with high quality can be obtained.

Moreover, in the second invention, a method for manufacturing a brass material having high mechanical strength and both mechanical properties and electrical properties can be obtained.

[Brief explanation of drawings]

1 to 3 show one embodiment of each invention, and the first
The figure is a process diagram, Figure 2 is a perspective view, and Figure 6 is a cross-sectional view. 1... Brass material, 5... Vacuum heating furnace, 12...
conductive layer. Patent applicant Matsushita Electric Works Co., Ltd. Representative patent attorney Toshimaru Takemoto (and 2 others)

Claims (2)

[Claims] (1) A brass material characterized by placing the brass material in a substantially vacuum atmosphere and heating it in the atmosphere above the boiling point of zinc to evaporate the zinc and form a conductive layer with a high copper content on the surface. Production method. (2) Brass material is placed in a near-vacuum atmosphere, heated above the boiling point of zinc in that atmosphere to evaporate the zinc, and after forming a conductive layer with a high copper content on the surface, it is rolled. Characteristic manufacturing method of brass material