JPH0631379B2 - Lubricant for plastic working of aluminum or aluminum alloy and plastic working method of the metal using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a lubricant for plastic working of aluminum or an aluminum alloy and a plastic working method using the same.

[Background of the Invention]

Aluminum or its alloys are widely used for parts such as sashes, cans and home appliances because of their light weight and good appearance. These parts are made by plastic working, which is mostly productive. In particular, cold forging, which has many advantages in terms of economy, is becoming the mainstream. In general, aluminum or its alloy parts are highly demanded for dimensional accuracy, surface condition (glossiness), etc. in order to give importance to the appearance, and special requirements are also placed on lubricants used during processing. For plastic working lubricants such as steel, it is necessary and sufficient to continue working under normal working load without seizure, whereas for aluminum and its alloys the above In addition to the above, the finished condition of the surface of the molded product must be good. Conventionally, in cold forging of aluminum or its alloys, mineral oil is used as a base oil, and oiliness improvers such as fatty acids, fatty acid esters, and higher alcohols, and extreme pressure agents such as tricresyl phosphite and trilauryl phosphite, or graphites. A lubricating oil containing a solid lubricant such as molybdenum disulfide is used. Since these lubricating oils have a composition that was considered with an emphasis on good surface properties after processing, they can only be applied to processing with a low processing rate with a small amount of deformation, and high temperature and high surface pressure. When manufacturing processed products with a high processing rate and complicated formation, the load resistance and heat resistance of the lubricating oil are not sufficient, so cracking, surface roughening, part deformation due to uneven plastic flow, seizure, etc. may occur. There is a limit to the range.

For seizure resistance, which is one of the major roles of lubricating oil for processing, a method of increasing the amount of oil taken into the friction surface between the die and the workpiece during processing is adopted. That is, it is considered that the property of wetting and spreading and the adhesion to the material to be processed should be improved. As such an example, one or more mono- or diphosphoric acid esters of polyoxyalkylene alkyl ether or polyoxylialkylene alkyl phenyl ether and one or more saturated or unsaturated fatty acid ester having 12 to 18 carbon atoms or higher alcohols. Lubricants for aluminum processing in which one or more kinds of metal soaps are mixed with mineral oil (JP-A-54-36303 or US Pat. No. 10872).
47) or a polyoxyalkylene derivative containing a higher carboxylic acid partial ester of a polyhydric alcohol, a higher alcohol alone or a mixture of both, and a phosphorus compound (JP-A-56-26997). Is mentioned. However, even with these lubricating oils, when the processing rate is high, there is a drawback that the surface properties are deteriorated and seizure is likely to occur.

On the other hand, there is a method in which a material to be processed is subjected to a pretreatment such as a chemical conversion film treatment and then the surface thereof is treated with a metallic soap.
In this case, seizure does not occur even in processing with a high degree of processing, and good performance is exhibited, but the surface is colored and the appearance is poor,
It cannot be said that this is a versatile lubrication method because finishing work such as machining is indispensable.

[Object of the Invention]

The present invention has conducted various studies to improve the drawbacks and problems of the prior art, and as a result, it is excellent even in complicated forming and processing conditions with a high degree of processing by only applying a lubricant to a work material made of aluminum or an aluminum alloy. The present invention provides a lubricant that exhibits a lubricating effect, improves the quality of processed products, and simplifies the processing process, and is particularly suitable for plastic working of aluminum and its alloys, and a working method using the same.

[Outline of Invention]

The lubricant of the present invention comprises a lubricating oil as a main component, to which one or more mono- or diphosphoric acid esters and one or more phosphorous acid esters of pentaerythritol are added.
Desirably, at least one or more kinds of lubricating oils of mineral oils and synthetic oils, the additive A, and the phosphoric acid ester of the polyoxyalkylene alkyl ether represented by the general formula (1) or (2) Alternatively, phosphoric acid ester of polyoxyalkylene alkyl phenyl ether represented by the general formula (3) or (4) (Wherein R ₁ and R ₂ are the same or different alkyl groups having 8 to 18 carbon atoms, R′O is an ethylene, propylene or butylene oxide group, and R ₃ and R ₄ are the same or different groups having 8 to 9 carbon atoms. One or more of an alkylphenyl group having an alkyl group, m, n, o, p, q, and r are integers, and an additive B, an alkylpentaerythritol mono- or diphosphite represented by the general formula (5). Alternatively, an alkylphenyl pentaerythritol mono- or diphosphite represented by the general formula (6) (Note that R ₅ is an alkyl group having 8 to 18 carbon atoms, and R ₆ is an alkylphenyl group having an alkyl group having 8 to 9 carbon atoms, but in (5) and (6), R may be H.) One or more of the above are blended.

The alkyl group (R ₁ , R ₂ ) in the general formulas (1) to (4) is
Groups such as octyl, isodecyl, lauryl, tridecyl, palmityl, stearyl, oleyl, etc., and alkylphenyl groups include nonylphenyl and octylphenyl groups. In addition, ethylene oxide is generally used as the alkylene oxide, and its unit valence mole number ((1)
And (3), m and p, (2) and (4) (n
+ O) 12 or (q + r) 12) is preferably about 2 to 15. Further, the alkyl group (R ₅ ) in the general formulas (5) to (8) includes octyl, isodecyl, lauryl, and the alkylphenyl group includes nonylphenyl and octylphenyl groups.

The additive A, one or more polyoxyalkylene alkyl ether or polyoxyalkyl phenyl ether phosphate ester, and the additive B, one or more alkyl pentaerythritol or alkyl phenyl pentaerythritol phosphate ester are blended. The properties of the lubricating oil composed of at least one of mineral oil and synthetic oil to be used can be arbitrarily selected according to the processing conditions and working conditions.
The viscosity at 0 ° C. is preferably 10 mm ² / S (CS _t ) or more. The blending ratio of the additives A and B to the lubricating oil may be arbitrarily selected according to the processing conditions.
A: B is preferably 5 to 95:95 to 5 (parts by weight), the total is preferably 2 to 60% by weight, and the lubricating oil is preferably used in the range of 98 to 40% by weight.

Examples of the lubricating oil used in the present invention include mineral oils, polyolefin oils, monoesters, diesters, polyol ester oils, polybutene, polyalkylene glycol oils, and mixed oils thereof.

As for the lubrication effect of the additives A and B, first, the component A achieves an improvement in the supply of the lubricant to the friction surface, and the deformation heat and friction heat during processing provide excellent lubricity on the surface of the workpiece. Form a lubricating coating. In addition, component B also forms a lubricating coating on the surface of the workpiece due to the heat during processing, improving the lubricity of the coating, reducing the processing load and heat resistance, and for products with a high degree of processing. Prevents seizure.

If the mixing ratio of the components A and B and the total amount of the components A and B to be added to the lubricating oil are less than the above range, a strong lubricating film is not formed on the surface of the workpiece and seizure occurs. Like In addition, if the number is large, no further effect appears.

It should be noted that solid lubricants such as graphite, molybdenum disulfide, tungsten disulfide, boron nitride, carbon fluoride, and Teflon, and extreme pressure agents such as organic chlorine and organic sulfur compounds may be arbitrarily added within a range that does not impair the object of the present invention. It can be blended.

When the lubricant of the present invention is applied to the processing of aluminum and its alloys, many cold workings such as deep drawing, drawing, wire drawing, rolling, ironing and extrusion can be easily achieved. It is possible to process complicated shapes with a high degree of processing in a single operation, and the surface finish of the processed product is good.

The aluminum material as the material to be processed is composed mainly of aluminum such as pure aluminum and aluminum and aluminum alloy materials described in JIS H4040. Further, the material of the die used for processing is not particularly limited, but a good processed product can be obtained even if the alloy tool steel and the alloy tool steel surface are hard-treated.

Example of Invention

Hereinafter, examples of the present invention will be described together with comparative examples, but the present invention is not limited to these examples.

Examples 1 to 13 Table 1 shows the lubricant compositions used for comparison and the lubricant compositions of the examples. After applying this lubricant to the surface of the aluminum alloy material to be processed, the processing performance and the maximum processing load, and the dimensional accuracy surface condition after processing were examined by the forward extrusion processing method under the following conditions. The results are shown in Table 2.

The processing conditions, dimensional accuracy, processing performance, and processing load measurement methods are as follows.

1. Processing conditions (1) Work material (a) Material: Aluminum alloy (JISA5056) (b) Dimensions: Outer diameter 9.9 mm, length 30 mm Surface roughness max 2.1 μm (2) Mold and main dimensions (a) Material: SDK11 (b) Container diameter: 10 mm (c) Extrusion angle: 120 degrees (d) Drawing diameter: 6 mm (processing rate 64%) 2. Dimensional accuracy This is the average value (10 measurements) of the deviation in diameter between the 5 mm and 50 mm parts from the end of the drawn diaphragm. If the dimensional accuracy was 0.09 or more, the tip was cracked. This occurs because the lubricating performance of the lubricant is low.

3. Processing performance The figure shows the cross section of the mold used to evaluate the performance of the lubricant. A band heater for heating the mold is attached to the front extrusion mold, and the mold temperature is raised stepwise every 5 to 20 ° C.
Processed material coated with lubricant at each temperature processing speed 15mm /
10 pieces each were processed under the condition of s, and the maximum mold temperature at which seizure did not occur on the surface after processing was measured. The higher this temperature, the more excellent the heat resistance of the lubricating coating formed on the surface of the workpiece during processing. That is, the processing performance of the lubricant is excellent.

4. Processing load A pressure converter was attached to the pressurizing pipe of the hydraulic press, and the pressure during processing was recorded with a recorder. The extrusion pressure during processing is greatly affected by the lubricity (friction coefficient) of the lubricating coating formed on the friction surface, and the larger the friction coefficient, the higher the extrusion pressure during processing. The processing load was evaluated at the maximum mold temperature at which seizure did not occur on the surface of the processed material after processing.

From the results shown in Table 2, according to the present invention, the workability was large, and even under extremely severe working conditions, the heat resistance and the lubricating performance of the lubricating coating formed during working were remarkably improved, and good results were obtained. Further, it is apparent that the processed material has no cracks at the tip thereof and has excellent dimensional accuracy and surface condition.

〔The invention's effect〕

The lubricant for plastic working of the present invention is, as is clear from the above examples, only by applying the lubricant to a material to be processed made of aluminum or an aluminum alloy, and the heat of processing causes heat resistance of the friction surface. Since the excellent lubricating film is formed, it is possible to process parts having a high workability and parts having a complicated shape as compared with conventional working oils, which greatly contributes to simplification of the working process and cost reduction.

[Brief description of drawings]

The figure is a vertical cross-sectional view of a forward extrusion mold used for evaluating the performance of a lubricant. 1 ... Punch, 2 ... Workpiece material, 3 ... Processing surface, 4 ...
Band heater for mold heating, 5 ... SDK 11 material part.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication C10N 30:08 40:24 A 8217-4H (72) Inventor Fumio Nakano 3 Saiwaicho, Hitachi City, Ibaraki Prefecture 1-chome 1-1 Hitachi Research Laboratory, Hitachi Ltd. (56) Reference JP-A-53-124153 (JP, A) JP-A-54-36303 (JP, A) JP-A-55-104394 (JP, A) )

Claims (2)

[Claims] 1. 5-95 parts by weight of a monophosphate and / or diphosphate and 95-5 parts by weight of an alkylpentaerythritol phosphite and / or an alkylphenylpentaerythritol phosphite are added to a lubricating oil. A lubricant for plastic working of aluminum or an aluminum alloy, characterized by being mixed in an amount of -60% by weight. 2. 5 to 95 parts by weight of a monophosphate and / or diphosphate and 95 to 5 parts by weight of an alkylpentaerythritol phosphite and / or an alkylphenyl pentaerythritol phosphite to 2 parts by weight of a lubricating oil. A lubricant mixed in an amount of -60% by weight is applied to the surface of a work piece made of aluminum or an aluminum alloy, and the work piece is formed in the presence of a lubricating film formed by plastic working of the surface of the work piece and the lubricant. A plastic working method of aluminum or an aluminum alloy, which comprises subjecting a worked material to plastic working.