Clamping Platen for Die Casting Machine and Manufacturing Method

Abstract

A clamping platen for a die casting machine has a base plate body of a cast iron material, a surface layer of a stainless steel material welded onto at least one plate side of the base plate body, and a transitional layer between the base plate body and the surface layer. The surface layer is applied as a laser weld application layer.

Claims

1. A clamping platen for a die casting machine, comprising: a base plate body of a cast iron material; a surface layer of a stainless steel material welded onto at least one plate side of the base plate body; and a transitional layer between the base plate body and the surface layer, wherein the surface layer is a laser weld application layer.

2. The clamping platen according to claim 1, wherein the surface layer and the transitional layer together have an application thickness of at most 2.5 mm.

3. The clamping platen according to claim 1, wherein the surface layer and the transitional layer together have an application thickness of at most 2.0 mm.

4. The clamping platen according to claim 1, wherein the transitional layer has a layer thickness of at most 0.5 mm.

5. The clamping platen according to claim 1, wherein the transitional layer has a layer thickness of at most 0.3 mm.

6. The clamping platen according to claim 1, wherein the transitional layer has a layer thickness of at most 0.15 mm.

7. The clamping platen according to claim 1, wherein the transitional layer has a layer thickness of at most 0.1 mm.

8. The clamping platen according to claim 1, wherein the surface layer is face-machined.

9. A method for manufacturing a clamping platen, the method comprising the steps of: providing a base plate body of a cast iron material with a plate side to be coated; and applying a surface layer of a stainless steel material onto the plate side to be coated by a laser weld application process, with formation of a transitional layer, wherein during the laser weld application process a laser beam spot is guided in rows over the plate side to be coated and a powdery stainless steel material is added, and weld application beads of the stainless steel material are formed which partially overlap transversely to the row direction.

10. The method according to claim 9, wherein the layer is applied in the laser weld application process with an application thickness of at most 2.5 mm, and after the laser weld application process, a facing process is performed which removes the surface layer down to a residual thickness of at least 1 mm and at most 2.2 mm.

11. The method according to claim 10, wherein the layer is applied in the laser weld application process with an application thickness of at most 2.0 mm.

12. The method according to claim 10, wherein the surface layer is removed down to a residual thickness of at least 1.4 mm and at most 2.0 mm.

13. The method according to claim 9, wherein for the base plate body, a cast iron material with spheroidal graphite is used.

14. The method according to claim 9, wherein for the powdery stainless steel material, a material is selected which contains between 16.0% and 22.0% chromium (Cr), 4.0% to 9.0% nickel (Ni), 0.4% to 6.0% manganese (Mn), 1.0% to 9.0% molybdenum (Mo), 0.03% to 0.4% carbon (C), and 0.1% to 0.8% silicon (Si).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 shows a schematic longitudinal section through a layer structure of a clamping platen of a die casting machine;

[0024] FIG. 2 shows a micrograph corresponding to FIG. 1 for a manufactured clamping platen;

[0025] FIG. 3 shows a schematic, perspective view to illustrate a laser weld application process which may be used for manufacturing the clamping platen; and

[0026] FIG. 4 shows a schematic, longitudinal sectional view to illustrate the laser weld application process.

DETAILED DESCRIPTION OF THE DRAWINGS

[0027] The clamping platen illustrated schematically in FIG. 1 and as a manufactured sample in FIG. 2, in a part area of interest here contains a base plate body 1 of a cast iron material, a surface layer 3 of a stainless steel material welded onto at least one plate side 2 of the base plate body 1, and a transitional layer 4 between the base plate body 1 and the surface layer 3. The surface layer 3 is in particular a laser weld application layer. The base plate body 1 may in particular consist of a cast iron material with spheroidal graphite.

[0028] To manufacture the clamping platen, firstly the base plate body 1 with the plate side 2 to be coated is provided. Optionally, the base plate body 1 is face-machined on its plate side 2 to be coated, i.e. its surface roughness is reduced by milling, grinding or other conventional facing processes. Then the surface layer 3 is applied to the plate side 2 to be coated by a laser weld application process, forming the intermediate transitional layer 4. During this laser weld application process, as illustrated schematically in FIGS. 3 and 4, a laser beam spot 5 is guided in rows over the plate side 2 to be coated and a powdery stainless steel material 6 is added. So a weld application bead 9 of the stainless steel material 6 is created along each row over which the laser beam spot 5 provided by the laser beam 7 moves, wherein the laser beam spot 5 is guided from one row to the next, from the left to the right in FIG. 3, such that respective adjacent weld application beads 9 partially overlap. As a powdery stainless steel material, in particular a commercial stainless steel welding material may be used which contains, in addition to the main constituent iron (Fe), between 16.0% and 22.0% Cr, 4.0% to 9.0% Ni, 0.4% to 6.0% Mn, 1.0% to 9.0% Mo, 0.03% to 0.4% C and 0.1% to 0.8% Si as minority constituents.

[0029] The process management for the laser weld application process may include for example the irradiation of the laser beam 7 with a power of 0.3 kW to 4.0 kW and an intensity between 10.sup.4 W/cm.sup.2 and 10.sup.5 W/cm.sup.2. Here, the cast iron material of the base plate body 1 liquefies superficially in the region of the laser beam spot 5, and a substance-bonded connection occurs with material bonding of the supplied powdery stainless steel material 6, which is melted in the region of the laser beam spot 5, with the superficially liquefied cast iron material. The powdery stainless steel material 6 is blown into the region of the laser beam spot 5, for example via a feed pipe 8 as shown, preferably under use of an inert gas such as argon or neon as a conveying gas. FIG. 4 illustrates schematically the formation of a heat influence zone 10 within which the cast iron material of the base plate body 1 liquefies superficially to the required extent, and a mixing zone 11 in which the material connection of the cast iron material and stainless steel material takes place, and on which then the primary stainless steel material is deposited in the form of the weld application bead 9 and hence the surface layer 3 is formed from the weld application beads 9.

[0030] In corresponding implementations, the surface layer 3 and the transitional layer 4 together have a layer thickness on the surface of the base plate body 1 of at most 2.5 mm and preferably at most 2.0 mm, e.g. approximately only 1.5 mm. Here, the transitional layer 4 in corresponding embodiments has a layer thickness du of at most 0.5 mm and preferably at most approximately 0.3 mm. In preferred embodiments, the layer thickness du of the transitional layer 4 is at most 0.15 mm, i.e. only around 0.15 mm or less, and in corresponding implementations only around 0.1 mm or less.

[0031] Optionally, after the end of the laser weld application process, the surface layer 3 formed from the individual weld application beads 9 is subjected to a facing process in which it is removed down to a residual thickness of at least 1 mm and maximum 2.2 mm, preferably to a residual thickness of at least 1.4 mm and maximum 2.0 mm. The surface layer 3 consequently has a final layer thickness do corresponding to this residual thickness, or in the case without facing, corresponding to the original application thickness of the surface layer 3 and transitional layer 4 less the layer thickness du of the transitional layer 4. Depending on the desired final flatness of the surface layer 3 and hence of the clamping platen on its coated plate side 2, for example between 0.4 mm and 0.6 mm of the original layer thickness of the surface layer 3 is removed in this facing process.

[0032] FIG. 2 illustrates in a micrograph an exemplary clamping platen manufactured in the manner explained above, in the surface region of interest here of its coated plate side 2. In this micrograph, the transitional layer 4 is clearly evident as a hard remelt zone with layer thickness du on the cast iron material of the base plate body 1, together with the surface layer 3 of stainless steel material with a layer thickness do rising from the transitional layer 4. This micrograph proves the formation of a substance-bonded, sufficiently homogenous connection of the corrosion-resistant surface layer 3 of the stainless steel material to the cast iron material of the base plate body 1 via the comparatively thin transitional layer 4.

[0033] If necessary, one or more further plate sides of the clamping platen may be provided with such a surface coating in the manner explained above with respect to plate side 2. As a whole therefore, according to the invention, a clamping platen is provided which has the specific laser weld application layer as a surface layer on only one or alternatively several plate sides, wherein the surface layer 3 can be formed with relatively little cost and if necessary relatively small layer thickness, with simultaneously good adhesion to the base plate body 1 and high resistance to corrosion and mechanical effects.

[0034] As the exemplary embodiments shown and those also explained above make clear, the invention provides a clamping platen with a highly advantageous surface layer of a stainless steel material which can be formed with relatively low production cost and offers high protection against corrosion effects and mechanical effects.

[0035] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.