DD137244B1 - LUBRICANT FOR STRESS PRESSURE - Google Patents

Description

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Lubricant for extrusion

Field of application of the invention

The invention relates to a lubricant for extruding metallic materials, in particular Nieh.teisen materials, in the temperature range of 300 to 600 C.

Characteristic of the known technical solutions

It is known to use graphite-based lubricants in the extrusion of metallic materials. From the application of graphite-containing lubricant is known that at press temperatures below 600 C, the lubricating effect is insufficient, so that the friction is only slightly reduced and high compressive forces are required for forming. Another disadvantage is that graphite carburizing the material to be pressed or partially burns and still adheres to the pressed material after extrusion. This results in a rough provided with adhesive lubricant residues surface of the material to be pressed. To remove the graphite residues, additional operations, e.g. Pickling, necessary.

Furthermore, the use of glasses with high contents of SiO _{2 is} known (Metal Industry 26.9.1958, p 249 ff; DD-PS 113566). The softening temperature of these glasses is significantly above 600 G, so that they at temperatures

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do not melt below 600 ^° C. and do not form a coherent film on the press stud. There are formed in the strand pressed, schlieren- and strip-shaped zones incompletely melted glass, which must be removed before further processing of the material to be pressed by pickling in hydrofluoric acid media and / or by mechanical treatment. A sufficient lubricating effect is achieved by such lubricants only at temperatures above 600 C. "For the strict compression of particular iron-Y.'erkstoffen which must be pressed at temperatures below 600 ⁰ C, such lubricants are therefore unsuitable. Pressing tempera doors above 600 ^} C are unfavorable because of non-ferrous metals and. their alloys form unwanted oxide layers and composite materials in intermediate phases, which adversely affect the flow behavior of the material and complicate the further processing dos pressed strand or exclude.

The aim of the invention is to develop a lubricant for extruding metallic materials, especially non-ferrous materials, which is applicable in the temperature range of 300 ° to 600 ⁰ C, leaves no disturbing residues on the material and da3 by its lubricating effect a reduction of friction and thereby enables a reduction of the pressing force.

Essence of the invention

The known lubricants for extruding metallic materials melt either. At a press temperatur below 600 ⁰ G not on or they adhere as a non-contiguous and difficult to remove layer on the pressed material.

The invention is based on the object, a lubricant for extruding metallic materials, in particular to develop light-iron materials, the composition in the pressing temperatür in the range of 300 ° to 600 ⁰ C has a suitable viscosity, completely melts and forms a coherent film.

According to the invention, the charge is achieved in that the lubricant for extruding metallic materials from an oxide mixture of 38 to 93% by mass lead (II) -o: xid, 60 to 5% by mass of boron oxide, rest of Siliziumdioxid'besteht. The proportion of silicon dioxide is at most 18% by mass. Lead (II) oxide can be replaced up to 1% by mass by adding up to 6% by mass of barium oxide and biting to 5% by mass of potassium oxide and up to 5% by mass of calcium oxide.

embodiment

The invention will be explained in more detail with reference to two exemplary embodiments.

Example 1:

A copper-clad niobium titanium ~ ~ block is preheated to 580 ⁰ C and covered after removal from the furnace with a pulverized Oxidgeraisch consisting of 73% by mass Lead (II) oxide, 20% by mass of boron oxide and 7% by mass of silica. The bolt provided with this oxide mixture is applied on an extruder with a maximum pressing pressure v <

Example 2%

A copper block is preheated to 500 ° C. and, in the preheated state, into an oxide mixture of 42 % by mass of lead (II) oxide, 35% by mass of boron oxide, 10% by mass of silicon dioxide,

ρ pressing pressure of 10 N / mm pressed.

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5 mass% Bariumo.xid _s 4% by weight potassium oxide and 4% by mass calcium oxide wrapped, so that the outer surface and the facing end face of the stamper are uniformly covered. Thereafter, the copper block is placed on a strand

Pressed 2 press with a pressure of 10 N / mm.

The advantage of the solution according to the invention is that the lubricant is flowable at extrusion temperature and due to its suitable viscosity completely on в с hmi1ζ t «

The lubricant is advantageous as an ausarmnenhängender film over the entire Preßrohling. The lubrication effect achieved thereby v / esentlich reduces the friction of the press blanks on the Aufnehmerwandung, so that the pressing force up to 50 % compared to the extrusion with graphite as Schmiermittel.bzw. can be reduced compared to extruding without lubricant. Furthermore, a uniform material flow is achieved by the lubricant in composite and solid materials, so that internal distortions are avoided in the pressed material, pie surface is free of pressing errors and lubrication telres th. The lubricant film v / eist after extrusion such a small thickness that he does not flake off, do not tear and make no bumps.

The lubricant film may remain on the material to be pressed for further processing. It is removed or torn at the respective stages of processing and does not need to be removed by additional operations.

Another advantage of the lubricant according to the invention is that it can be extruded in a narrow temperature range and so-called temperature-sensitive materials can be produced to quality. Overall, the production of Preßhalbzeug with perfect surface with reduced energy consumption is possible with the application of the proposed lubricant.

Claims (3)

Erfindungoanaprucru 1. A lubricant for extruding metallic materials, in particular non-ionic V / erkstoffe, Tempe in the temperature range of 300 ° to 600 ⁰ G, characterized in that it consists of an oxide mixture of 38 to 93% by weight of lead (II) oxide, 60 to 5 Мачзе- # Boroxide and mindflsttfn ;: 2 mass% Sxlizj шааіохіа commits «, 2. Lubricant for extrusion according to item 1, characterized in that the proportion of silicon dioxide is a maximum of 18 leases - '/ j. 3. Lubricant for extruding according to l'ure.kt 1, characterized in that lead (II) oxide is replaced up to 16 Ма ^ че- ^ by adding a quantity of I to 6 Иѵ.взс-% bariumoidLd and up to 5 Mass- ^ potassium oxide and am to 5 mass% of potassium oxide.