JPS5893801A - Manufacture of sintered article of powder - Google Patents

Abstract

PURPOSE:To obtain a sintered article of powder having fine appearance and high performance by using a polyoxyalkylene compound as a lubricant during sizing which is carried out between preforming and final sintering. CONSTITUTION:A preformed and presintered article is coated or impregnated with a polyoxyalkylene compound such as polyoxypropylene glycol monobutyl ether as a lubricant, and it is molded again, heated and sintered again under prescribed conditions. By this method a sintered article of powder causing no sticking of foreign matter and no discoloration after the final sintering is obtd.

Description

[Detailed description of the invention] It is.

In particular, the present invention relates to a method for producing a powder sintered article using a polyoxyalkylene compound as a lubricant during sizing after preforming.

Processing by powder sintering is widely used to manufacture parts that were conventionally manufactured by cutting, casting, and forging because of its resource-saving and energy-saving properties.

Rounding improves processing accuracy during powder sintering.

After preforming, a sizing process is performed by applying or impregnating a lubricating oil called a sizing agent, and then finally sintering is performed.

Mineral oil, animal and vegetable oils, etc. are usually used as the lubricating oil in this case, but the lubricating oil is carbonized during sintering, which adversely affects the performance and aesthetics of the sintered article.

To avoid this, there is a method in which the material is washed with a solvent before sintering and then heat treated in an oxidizing atmosphere after sintering, but this method increases the number of steps and is not preferable.

An object of the present invention is to provide a lubricant during sizing processing that does not adversely affect the performance of powder molded articles.

The method for producing a powder sintered article of the present invention is characterized by using a polyoxyalkylene compound as a lubricant during the sizing process performed between preforming and final sintering.・The polyoxyalkylene compound used in the present invention has +RO-)H (in the formula, R is an alkylene group) in the molecule, preferably a lower alkylene group, such as a group derived from ethylene oxide or propylene oxide, and n is an oxyalkylene chain. It is a compound containing a group represented by polymerization &t-the number shown.

The polyoxyalkylene compound of the present invention can be obtained, for example, by adding a G alkylene oxide such as ethylene oxide or propylene oxide to an active hydrogen-containing compound.

active hydrogen-containing compounds, such as alcohol tA
(1m alcohol such as methanol, ethanol, butanol, octatool, ethylene glycol, propylene glycol, diol such as 41-butanediol, glycerin, trimethylolpropane, trivalent alcohol such as bentaerys 9)-v, tsuruhito-ru, etc. or more alcohol,
% phenols (phenol, cresol, etc.), amines (butylamine, ethylene diane, etc.).

Carboxylic acids (vinegar, propionic acid, nonanoic acid, oleic acid, etc.) and the like can be used.

Preferred polyoxyalkylene compounds of the present invention include methanol, ethanol, iso, propanol, butanol, glycerin, propylene glycol, etc. as active hydrogen compounds, and ethylene oxide and/or/ as alkylene oxides. Obtained using propylene oxide, molecular weight -0
The lubricant used in the present invention contains an oiliness improver (stearin ai) in addition to a polyoxyalkylene compound.

Fatty acids such as oleic acid, lower alkyl esters thereof such as methyl esters, metal soaps thereof such as zinc soap, and higher alcohols such as stearyl alcohol and myristyl alcohol), antioxidants (BHT, BHM, etc.) ),anti-rust! It may also contain a penetrant or the like.

The powder sintering method of the present invention is suitable for sintering powders of iron, copper, stainless steel, alloys, etc.
It can also be used for ceramics, etc.

If the lubricant of the present invention is used, it is generally not necessary to remove the lubricant by washing or the like after the sizing process, but washing may be performed if necessary, such as when a particularly clean product is desired. When cleaning, it is preferable to use glycols or ethers as the latent solvent.

less than! The present invention will be explained by referring to Examples and Comparative Examples.

Practical Example and Comparative Example Raw iron powder is mixed with stearic acid, zinc phosphate, and T56, formed into a complicated shape, and pre-sintered.The product is immersed in the lubricant shown below, and after reshaping, it is heated at 0°C for 10 minutes. Heat it up.

Ill! 1 lct was sintered at 00°C.

of the article after sintering! ! ! The surface condition and the state of rust formation after spraying salt water at 30° C. for a period of time were observed in accordance with the salt spray test of JS BZ-JJ7/.

The lubricants tested have the following formula: Mucopolyoxy 10 pyrene glycol monobutyl ether (molecular weight toao) B=polyoxyethylene polyoxyfa pyrene glycol monobutyl ether C molecular weight aooo) C: Mu9 by weight ~ and methyl stearate 1% by weight mixture D: polyoxin robylene glycol glyceryl ether (molecular weight too) qv type weight and olein@/°% by weight mixture I! ! : Polyoxypropylene glycol (molecular weight &o
o) Mixture of qr% by weight and 1% by weight of tallow fatty acid methyl ester F = Nidibutylamine propylene oxide adduct (molecular weight t-2oo) G: Propylene oxide adduct of octylic acid (molecular weight 7
00) Propylene oxide adduct of 11 nigeresol (molecular weight 1ooo) ■ (Comparative example): Commercially available industrial lubricating oil (Iso va reference 6)
J (comparative example): Beef tallow teX, rapeseed oil-0X.

A mixed product made of mineral oil 60X1 anti-rust additive tOX.

Evaluation result: Good No BI
IQ I
ID
j I-111 F I
IG I
IHL
l J I
1. In the samples obtained by the method of the present invention (A-me), there was no adhesion of foreign matter or discoloration after sintering, and no rusting was observed after spraying with salt water.

Patent applicant: Asahi Denka Kogyo Co., Ltd. Procedural amendment (voluntary) Nokozuki, 1923, 3rd anniversary Commissioner of the Patent Office 1.Display of the incident Method for manufacturing powder sintered articles 3. Person who makes corrections Relationship to the incident: Patent applicant Name (aSS) Asahi Denka Kogyo Co., Ltd. 4. Agent (2) 512 of the gAJI book! I don't understand the explanation. Contents of correction (1) Amend the claims as per the attached sheet.

(The statement in parentheses in the column before the amendment in the following section of the 21 Specification is amended to match the statement in the cup in the column after the amendment.

//Co “After forming” “After forming and sintering” Co l
``Goed'' ``Sintered and performed'' 3 ``Sintering''``Re-sintering'' ``Type 61 and final'' ``Sintering and final after type F'' ``Co 16 ``
``Sintering''``Resintering'' / ``Preliminary sintering''
"Sintering" s ts r Sintering""Resintering" s ts "Sintering""Resintering"
Paper Patent Claims Powder sintering characterized by applying or impregnating a powder sintered article that has been preformed and sintered with a lubricant containing a polyoxyalkyleno compound as a main component, reshaping it, and then resintering it. A method for producing a bound article.

Claims (1)

[Claims] 1. A method for producing a powder sintered article, which comprises applying or impregnating a preformed powder sintered article with a lubricant containing a polyoxyalkylene compound as a main component, shaping the article again, and then sintering it.