GB2204518A

GB2204518A - Apparatus for composite continuous casting

Info

Publication number: GB2204518A
Application number: GB08811290A
Authority: GB
Inventors: Robert William Johnson
Original assignee: DUNDEE COLLEGE OF TECHNOLOGY
Current assignee: DUNDEE COLLEGE OF TECHNOLOGY
Priority date: 1987-05-13
Filing date: 1988-05-12
Publication date: 1988-11-16
Anticipated expiration: 2008-05-12
Also published as: GB8811290D0; GB2204518B; GB8711279D0

Abstract

A die device (10) has inlets (11, 12) which lead to first and second passages (14, 22) respectively. The first passage (14) has an upstream portion (15) for cooling and solidifying a first metal, and a downstream portion (16); and the second passage (22) has an upstream portion (21) for cooling and solidifying the second metal, said portion (21) being contiguous with the downstream portion (16) of the first passage. Thus, the second metal is solidified and cooled in intimate contact with the solidified first metal. In one embodiment (as shown) an insert in the upstream portion (15) creates a groove in a side of the first metal which faces the second metal inlet, thus the second metal forms an inlay in the first. In other embodiments, composite hollow tubular products are made. <IMAGE>

Description

CASTING APPARATUS The present invention relates to the production of multimetallic components made up of two or more metallic moieties each of which may be a more or less pure metal or an alloy, secured to each other. Such components are used in various fields but especially in the electronics and electrical engineering fields. One example that may be mentioned is in the field of connectors where a high conductivity inlay e.g. of gold is provided on a lower conductivity conductor element e.g. of copper or brass.

Conventionally multimetallic components are manufactured by separate formation of each of the different metallic moieties and then securing of the discretely formed moieties to each other by a suitable process such as roll-forming, accompanied if necessary by additional heat treatment in order to enhance intermetallic bonding.

It will be appreciated that such a process is not only relatively slow and cumbersome but also very expensive to operate.

It is an object of the present invention to avoid or minimize one or more of the above disadvantages.

The present invention provides a die device suitable for use in the continuous casting of multimetallic components which device comprises a die body having a first passage means having an upstream portion for cooling and solidification of a first metallic moiety introduced thereinto and a downstream portion and at least one second passage means having an inlet portion separated from said first passage means leading into an upstream portion extending contiguously with said first passage means downstream portion for cooling and solidification of at least one second metallic moiety introduced via said inlet portion,contiguously with the solidified first metallic moiety passing therethrough in use of the device.

Thus with a device of the present invention it is possible automatically to form multimetallic components in a simple and economic manner and with good bonding between the different metallic moieties.

Preferably there is provided an internal annular collar means upstream of a or each said second passage inlet portion but downstream of an immediately preceding passage upstream portion, and having an internal diameter less than that of said upstream portion by an amount corresponding substantially to the shrinkage of the casting upon solidification within said upstream portion.

In a further aspect the present invention provides a continuous casting apparatus suitable for use in the continuous casting of multimetallic components comprising a furnace having a first chamber for holding a molten body of a first metallic moiety and at least one second chamber for each holding a molten body of a second metallic moiety, and a die device of the invention with said first and second chambers connected to said first and second passage means of said die device by respective conduit means.

In another aspect the present invention provides a method of producing a multimetallic component comprising the steps of continuously casting a first metallic moiety of said component and allowing said moiety to solidify and then continuously casting a second metallic moiety contiguously with the solidified first moiety and allowing said second metallic moiety to solidify.

Further preferred features and advantages of the present invention will appear from the following detailed description given by way of example of a preferred embodiment illustrated with reference to the accompanying drawings in which: Fig. 1 is a plan view of part of an apparatus of the invention comprising a multi-metal crucible; Fig. 2 is a schematic front elevation of the crucible of Fig. 1; Fig. 3 is a plan view of a first die of the invention; Fig. 4 is a longitudinal section taken on line IV-IX' of Figure 3; Figs. 5 and 6 are corresponding views of a second die, and Fig. 7 is a longitudinal section of a third die.

Fig. 1 shows a graphite crucible 1 having a plurality of separate compartments 2, 3, 4 for holding different molten metals which are to be continually cast.

The chambers 2-4 have respective outlet conduits 5-7 which are connected in use of the system with a die device as described further hereinbelow. Fig. 3 shows a die device 8 comprising an outer support member 9 for a die member 10 which has a primary molten metal inlet 11 and a secondary molten metal inlet 12 at one surface 13 thereof. The primary inlet 11 leads into a metal passage 14 which extends along the length of the die member 10 and has an upstream portion 15 and a downstream portion 16 which extends beyond the primary metal solidification front 17'. As may be seen in Fig. 3, the primary metal passage is substantially rectangular in cross-section with one face 18 having a rectangular shallow recess defined therein and receiving a bar form insert 19.

The secondary metal inlet 12 extends via a conduit 12a through the die member 10 generally alongside the metal passage 14 to a inlet portion 20 at which the secondary metal enters an upstream portion 21 of a lower metal passage 22 which extends contiguously with the first passage, the cross-section of the metal solidifying in the metal passage 22 corresponding to that of the metal passage 14 modified by the bar insert 19 so that in use of the die device, the secondary metal forms an inlay in the primary metal.

In order to prevent any problems associated with backs low of secondary metal along the small gap between the contracted solidified primary metal bar passing along the metal passage 14, an annular ceramic insert 23 having an internal diameter selected so as to correspond closely to the external diameter of the contracted primary metal bar, is mounted upstream of the secondary metal inlet 24 to the primary metal passage 14 but downstream of the primary metal solidification front 17.

The support 8 is conveniently provided with cooling pipe means 25 to facilitate control of the cooling and solidification of the primary and secondary metals within the die 10.

The die device of Figs. 5 and 6 is generally similar to that of Figs. 3 and 4, like parts being identified by like reference numbers. In this case, there are provided four primary metal inlets 11 and two secondary metal inlet systems 26, 27, each of which systems is divided into a plurality of conduits 28 for feeding discrete inlay strips at 29, 30 contiguous with the main body of the primary metal. It may also be noted that the primary metal passage 14 is annular, a tapered mandrel 31 being provided along the central axis 32 of the primary passage 14. It will be observed that a second ceramic insert 23' is provided between the upstream and downstream levels of the mouths of the inlets 28. The metal solidification front of the metal entering at the downstream inlets 28 is indicated at 17".

A further example of the present invention is shown in Fig. 7, which shows features of Figs. 4 and 6, like parts being identified by like reference numbers.

In this example, the primary molten metal inlet 11 leads into a primary metal passage 14, which extends along the length of die member 10, and has an upstream portion 15 and a downstream portion 16, which extends beyond the primary metal solidification front 17 where a solidified hollow annular section is produced.

An inlet 12 for the second molten metallic moiety extends via a conduit through a tapered core or mandrel 31 being provided along a central axis 32 of the primary passage 14. The secondary molten metallic moiety enters an upstream portion 21 of the secondary metal passage 22, and solidifies at position 35 to produce an internal core 36 bonded to the external metallic moiety 38.

Claims

1. A die device suitable for use in the continuous casting of multimetallic components which device comprises a die body having a first passage means having an upstream portion for cooling and solidification of a first metallic moiety introduced thereinto and a downstream portion and at least one second passage means having an inlet portion separated from said first passage means leading into an upstream portion extending contiguously with said first passage means downstream portion for cooling and solidification of at least one second metallic moiety introduced via said inlet portion, contiguously with the solidified first metallic moiety passing therethrough in use of the device.

2. A device as claimed in claim 1 wherein means are provided to project into the upstream portion of the first passage means to control the formation of a groove or recess in the solidified first metallic moiety to receive said second metallic moiety as an inlay.

3. A device as claimed in claim 1, wherein core means are provided centrally of said first passage means to control the formation of the solidified first metallic moiety in a hollow tubular configuration, the second passage means passing through said core means to provide second moiety metal to the interior of the tubular solidified first moiety.

4. A device as claimed in any one of the preceding claims, wherein there is provided an internal annular collar means upstream of a or each said second passage inlet portion but downstream of an immediately preceding passage upstream portion, and having an internal diameter less than that of said upstream portion by an amount corresponding substantially to the shrinkage of the casting upon solidification within said upstream portion.

5. A continuous casting apparatus suitable for use in the continuous casting of multimetallic components comprising a furnace having a first chamber for holding a molten body of a first metallic moiety and at least one second chamber for each holding a molten body of a second metallic moiety, and a die device according to any one of the preceding claims with said first and second chambers connected to said first and second passage means of said die device by respective conduit means.

6. A method of producing a multimetallic component comprising the steps of continuously casting a first metallic moiety of said component and allowing said moiety to solidify, and then continuously casting a second metallic moiety contiguously with the solidified first moiety and allowing said second metallic moiety to solidify.

7. A method as claimed in claim 6, wherein said second metallic moiety is continuously cast in a recess formed on a surface of the solidified first metallic moiety to form an inlay or fillet.

8. A method as claimed in claim 6 wherein said second metallic moiety is continuously cast in a hollow central region of the solidified, annular section, first metallic moiety.

9. A die device suitable for use in the continuous casting of multimetallic components, constructed and arranged substantially as hereinbefore described with reference to and as shown in a) Figures 1-4, b) Figures 5, 6, c) Figure 7 of the drawings.

10. A continuous casting apparatus suitable for use in the continuous casting of multimetallic components constructed and arranged substantially as hereinbefore described with reference to and as shown in a) Figures 1-4, b) Figures 5,6, c) Figure 7 of the drawings.

11. A method of producing a multimetallic component substantially as hereinbefore described with reference to a) Figures 1-4, b) Figures 5,6, c) Figure 7, of the drawings.