US3111731A

US3111731A - Die construction

Info

Publication number: US3111731A
Application number: US767842A
Authority: US
Inventors: Breining Elmer Robert; Wilbur M Bolton
Original assignee: Union Carbide Corp
Current assignee: Union Carbide Corp
Priority date: 1958-10-17
Filing date: 1958-10-17
Publication date: 1963-11-26
Anticipated expiration: 1980-11-26

Description

1963 E. R. BREINING ETI'AL 3,111,731

DIE CONSTRUCTION Fileq Oct. 17, 1958 2 Sheets-Sheet 1 INVENTORS. 2 MR ROBERT BRE/N/A/G W/LBl/R M. 011.70% r 8Y7 Z, Z

Nov. 26, 1963 E. R. BREINING ETAL 3,111,731

DIE CONSTRUCTION Filed Oct. 1'7, 1958 2 Sheets-Sheet 2 MOLD W/T (DA TO0R50 SURFACE EXPOSD HEAT METAL BEAR/N6 FROM MOLD DIE 0F 6A5 PLAYED METAL.

IN V EN TORS.

E ER ROBER RE/N/NG v/ral/R M. T B

ATTORNEY United States Patent 3,111,731 DIE CQNSTRUETIQN Elmer Robert Breining, Dayton, and Wilbur M. Bolton, Fiqua, Gino, assignors, by mesne assignments, to Union Carbide Corporation, New York, N.Y., a corporation of New York Filed Oct. 17, 1.953, Ser. No. 767,842 3 Claims. ((31. 22-193) This invention relates to dies and particularly to dies for metal stamping operations; the invention further relates to methods of producing the dies.

The invention has a principal object the provision of dies which consist essentially of metal deposited from heat decomposable metal bearing gaseous compounds. Such dies have very desirable characteristics, including good tensile strength and hardness, excellent ductility, a dense, continuous, non-laminar, substantially stress-free structure, good wear resistance, and an excellent capacity for resisting distortion. Further, complex contours are readily obtained in the dies and fine detail is retained under working conditions. Accordingly the dies are capable of long service life, providing for a very considerable economy.

The invention has as an important object the provision of a novel method of manufacturing dies which involves the deposition of gas-plated metal in substantial thickness on relatively inexpensive molds from which the body of gas plated metal is releasable without deformation of the plated metal, but which material conducts heat sufficiently to provide the contoured mold surface at temperatures effective for thermal decomposition of metal bearing ases. g The invention will be more fully understood by reference to the following detailed description and accompanying drawings wherein:

FIGURE 1 is an elevational view illustrating a mold having a contoured surface for use in forming the die of invention;

FIGURE 2 is a view similar to that of FIGURE 1 but with parts in section and the gas plated metal formed on the mold surface;

FIGURE 3 is a view of the body of gas plated metal of FIGURE 2 after removal from the mold; and

FIGURE 4 is a flow sheet illustrating the process of invention.

Referring to the drawings, the numeral 1 designates a mold of a heat conductive, non-porous, temperature-resistant material which may be formed by any usual mechanical operation to provide a configurated surface indicated at 2. The material should be sufiiciently heatconductive such that a substantially uniform temperature over the surface 2 may be obtained by any convenient heating means. It is important that the material I be relatively non-porous in order to provide the surface 2 relatively smooth.

It is further important that the material 1 be sufficiently heat-resistant to withstand the temperature at which the thermally decomposable compound decomposes to deposit metal. Also the mold material preferably has a coefficient of thermal expansion closely approaching that of the metal to be deposited.

Materials useful for the molds include metals, e.g. iron.

As illustrated in FIGURE 1 the mold is designed for heating with hot oil which is passed through the coil inlet 3 through the coil 4 to the outlet 5.

The numeral 6 in FIGURE 1 designates a thermocouple embedded in the body of the mold. Such thermocouples may be disposed throughout the length and width of the mold, depending upon the mold size.

Referring now to FIGURE 2, the numeral 7 designates a body of gas plated metal, having a lower surface 8 cated in FIGURES 2 and 3.

3,lil,73 l Patented Nov. 26, 1963 formed on the surface 2 of the mold. The body of gas plated metal has an upper surface & which is very generally the same contour as the lower surface 8 and the surface 2. However, the surface 9 need not be in exact conformity with the surface 8 for use of the gas plated metal body 7 as a die. The gas plated body is itself illustrated in FIGURE 3 after removal from the mold l.

in the process of invention, the steps of which are indicated in FIGURE 4, the Working body of gas plated metal designated at 7 is formed by gas plating a heat decomposable metal bearing compound onto the surface 2 of the mold I. For example, where nickel forms the body of gas plated metal the heat decomposable compound may be nickel carbonyl.

The deposition of the metallic nickel may be effected by subjecting the surface 2, in an enclosure at normal atmospheric pressure and at a temperature of 350 F., to an atmosphere of the heat decomposable nickel carbonyl. A carrier gas such as carbon dioxide may be employed to present the carbonyl to the mold surface. The temperature of deposition would, of course, be adjusted with other heat decomposable metal bearing compounds to effect the deposition at the most desirable temperature for the compound. A substantially uniform thickness of coating is obtained by the gas plating process as indi- To aid uniformity of thickness the coil 4 is formed to approach the surface 2 at substantially the same distance throughout the length of the surface.

if desired the mold may be lightly dusted with a lubricant, such as graphite, to assist removal of the die from the mold. Such graphite does not interfere with the deposition of the gas plated met-a1; however, such is not generally necessary.

T o attain the material thicknesses contact of the metal bearing gas with the mold is effected over a period of many hours, usually in excess of a day, and the plating operation is continuous. This is to avoid any striations which might occur should there be a lapse in the deposition of the metal. Such striations are undesirable, and when the plating is performed in a continuous manner the result is a dense, non-laminar, continuous metallic die structure having a surface formed to the predetermined contour, such as that at Z in FIGURE 1. The die of the desired configuration or contour is readily strippable from the mold without flexing or distortion of the die (FIGURE 3).

The surface 2 is the complement of the surface 8 and accordingly the mold 1 is formed with the surface 2 such as to provide the desired contour at 8.

The deposit of metal from the gaseous state is subtantially a pure body, which is important in connection with a die manufacture, since in use the die is subjected to considerable stress and wear. The purity of the deposit of nickel, for example, is well over 99 percent nickel, that is materially less than 1 percent of impurity. It has been found that a slight impurity, for example, carbon to the extent of 0.05 percent, is not at all detrimental to the utilization of the gas deposited metal as a die.

The contour of the working surface 8 is the complement of the mold surface 2 and is a smooth finish; the brightness of the finish depends on the mold surface and may be dull or mirror-like.

It is to be noted that while reference has been made hereinbefore to a die, that the article of manufacture may be either a stationary die or a movable die, commercially termed a punch. Further, the dies may be backed to provide for use in various types of operation.

Also, while the specific die illustrated has sharp corners, the die configuration may of course be curvilinear over a portion or all of the surface.

The die body of gas plated metal for press operations may be relatively massive and comparable dimensionally to dies produced by expensive time consuming hand operation. Despite the massive nature of the gas plated metal body it is substantially stress-free, which contributes to a long working life.

it Will be understood that this invention is susceptible to modification in order to adapt it to difierent usages and conditions and accordingly it is desired to comprehend such modifications within this invention as may fall Within the scope of the appended claims.

What is claimed is:

1. The process of manufacturing metal dies for use in metal stamping operations and which consists in providing a metal mold having a mold surface contour complementary to that of the die surface to be produced, coating said mold surface with graphite to form a smooth, non porous surface for receiving a metal deposit which is releasable therefrom, heating the resultant graphite coated mold, contacting the mold While thus heated With a thermally decomposable gaseous metal compound to cause said metal compound to decompose and deposit metal on the graphite coated mold surface and continuing the deposition of metal for several hours Without interruption to form a metal die body of said metal deposit which is relatively massive and of substantial thickness, and mechanicaliy separating said metal die body from the mold surface.

2. The process of manufacturing metal dies for use in metal stamping operations and which consists in providing a heat resistant mold having a mold surface contour complementary to that of the die surface to be produced, coating said mold surface with graphite to form a smooth, nonporous surface for receiving a metal deposit which is releasable therefrom, heating the resultant graphite coated mold, contacting the mold while thus heated with a thermally decomposable gaseous metal compound to cause said metal compound to decompose and deposit metal on the graphite coated mold surface and continuing the deposition of metal for at least a day to form a metal die body of said metal deposit which is relatively massive and of substantial thickness and free of striations, and mechanically separating said metal die body from the mold surface.

3. The process of manufacturing a die Which comprises the steps of: (a) providing a mold having a surface complementary to that of the surface of the die to be formed, said mold surface presenting a smooth, non-porous substrate, (b) lightly dusting powdered graphite particles over the said surface of the mold to assist in removal of the die from the mold after forming the same, (c) heating the mold, (d) exposing the mold to a heat-decomposable gaseous metal bearing compound continuously for several hours to effect decomposition of the compound with resultant deposition and build up of a body of metal on the said die surface to a substantial thickness, and (e) Without flexing or distortion of the deposited body of metal mechanically separating the metal body from the mold.

References Cited in the file of this patent UNITED STATES PATENTS 749,725 Fehr Jan. 19, 1904 1,193,928 Schroeder Aug. 8, 1916 1,464,526 Gutman Aug. 14, 1923 1,935,916 Ragsdale Nov. 21, 1933 2,254,516 Farr Sept. 2, 1941 2,281,634 Stossel May 5, 1942 2,293,571 Stossel Aug. 18, 1942 2,619,433 Davis Nov. 25, 1952 2, 38/123 Davis May 12, 1953 2,701,901 Pawlyk Feb. 15, 1955 2,834,690 Marvin May 13, 1958 2,889,598 Lundguist June 9, 1959 2,891,303 Stevenson June 23, 1959

Claims

1. THE PROCESS OF MANUFACTURING METAL DIES FOR USE IN METAL STAMPING OPERATIONS AND WHICH CONSISTS IN PROVIDING A METAL MOLD HAVING A MOLD SURFACE CONTOUR COMPLEMENTARY TO THAT OF THE DIE SURFACE TO BE PRODUCED, COATING SAID MOLD SURFACE WITH GRAPHITE TO FORM A SMOOTH, NONPOROUS SURFACE FOR RECEIVING A METAL DEPOSIT WHICH IS RELEASABLE THEREFROM, HEATING THE RESULTANT GRAPHITE COATED