CN100473481C - Powder metallurgy Fe-Cu-Sn oil-retaining bearing and manufacturing technique thereof - Google Patents

Abstract

The invention relates to a powder metallurgy Fe-Cu-Sn oil-retained bearing and the production process for the bearing. The bearing essentially comprises the following raw materials by weight: -100 mesh reduction Fe powder 96.5 swung dash 98%, -325 mesh Cu-Sn powder 2 swung dash 3.5%, lithium stearate 0.6 swung dash 1.0%. Wherein, in Cu-Sn alloy, Cu:Sn=7:2.5 swung dash 3.5 by weight. The production process is: weighing -100 mesh reduction Fe powder, -325 mesh Cu-Sn powder and lithium stearate by proper proportions; mixing them in a double-conic mixer at 19 swung dash 21r/min for 30-35 min; pressing the mixture under 300MPa swung dash 450MPa into blanks for oil-retained bearing; sintering the pressed blanks for 20-30 min under 880 swung dash 900 Celsius system, so sintered blanks are obtained; finishing and soaking by lubricating oil. The invention is of high strength, high oil content, low friction coefficient, low copper content, low material cost and process cost.

Description

Powder metallurgy Fe-Cu-Sn oil-retaining bearing and production technology thereof

Technical field

The present invention relates to a kind of bearing, especially relate to a kind of powder metallurgy Fe-Cu-Sn oil-retaining bearing and production technology thereof.Belong to powder metallurgical technology.

Background technology

Powder metallurgy oil-impregnated bearing is because its distinctive self-lubricating property and damping capacity occupy critical role in national economy.Be broadly divided into bronze oiliness bearing, iron-bronze oiliness bearing, iron-graphite oiliness bearing, iron-carbon oiliness bearing, iron/copper oiliness bearing and iron/copper-carbon oiliness bearing according to matrix material.Iron-graphite oiliness bearing wherein, iron-carbon oiliness bearing and iron/copper-carbon oiliness bearing cost of raw material is low, but because running noise is bigger, the coefficient of friction height, corrosion resistance is lower, and purposes is very limited; Bronze oiliness bearing, and iron a series of-bronze oiliness bearing with it, iron/copper oiliness bearing running noise is little, and coefficient of friction is lower, and decay resistance is all better, but intensity is lower, can not be used for the heavy load purposes.Wherein iron/copper oiliness bearing cost is relatively low, intensity higher (radial crushing strength 260Mpa), and purposes is extensive gradually.But in short supply along with nonferrous metal resource, because of containing 20% copper in the iron/copper oiliness bearing, cost is higher, and it is low therefore to be necessary to develop a kind of copper content, finished product bearing intensity height, oil content height, the new oil containing bearing material that coefficient of friction is little.

Summary of the invention

The objective of the invention is to overcome above-mentioned deficiency, provide a kind of copper content low, finished product bearing intensity height, oil content height, powder metallurgy Fe-Cu-Sn oil-retaining bearing that coefficient of friction is little and production technology thereof.

The object of the present invention is achieved like this: a kind of powder metallurgy Fe-Cu-Sn oil-retaining bearing is characterized in that: described bearing mainly is made up of following raw materials by weight percent:

-100 orders reduction Fe powder 96.5～98%

-325 order Cu-Sn powder 2～3.5%

Lithium stearate 0.6～1.0%,

Cu:Sn=7:2.5 in the Cu-Sn alloy～3.5 weight ratios wherein.

The production technology of powder metallurgy Fe-Cu-Sn oil-retaining bearing of the present invention mainly may further comprise the steps:

Step 1, batching

Take by weighing-100 orders reduction Fe powder ,-325 order Cu-Sn powder and lithium stearates by proportioning;

Step 2, mixing

The material for preparing rotating speed with 19～21r/min in double cone mixer mixes 30～35min, makes compound,

Step 3, pressed compact

Compound is pressed into the oiliness bearing pressed compact under 300Mpa～450Mpa pressure,

Step 4, sintering

Pressed compact at 880～900 ℃ of following sintering 20～30min, is obtained sintered blank,

Step 5, finishing and soaking by lubricating oil.

The Cu-Sn powder that the present invention introduces former because: the low melting point of utilizing the Cu-Sn powder, form liquid phase in sintering process, the at first wetting Fe skeleton of liquid phase is diffused in the sintering neck in the skeleton then, skeleton is expanded, obtain the product of interconnected porosity height (26%～35%).And the interconnected porosity height can promote oil content under same porosity, the bearing self-lubricating property is improved and the energy stable for extended periods of time; After cold cut, the Fe skeleton of bearing makes the strength enhancing (radial crushing strength 460Mpa) of bearing owing to the solution strengthening of Cu-Sn, and because the coefficient of friction low (0.01～0.015) of Fe-Cu-Sn alloy can make the bearing serviceability promote.

Use the oiliness bearing of this material, porosity is at 20%～30% o'clock, radial crushing strength 350Mpa～480pa, oil content 26%～35%, coefficient of friction 0.01～0.015.Cu:Sn=8:2 or when higher, because alloy melting point improves, the sintering temperature that reach the required employing of same intensity will be brought up to 1000 ℃ in the Cu-Sn alloy production cost is promoted, and because Sn content reduces, coefficient of friction increases.Cu:Sn=6 in the Cu-Sn alloy: 4 or when lower, because may generate the η phase of Cu-Sn, η phase fusing point is 415 ℃, intensity is only suitable with metal Sn, and the intensity of bearing material is significantly reduced.Reach peak value at the Cu-Sn alloy addition 2.6% o'clock intensity, increase alloy content intensity thereafter again and progressively reduce.The powder metallurgy oil-impregnated bearing that adopts the present invention to produce, the intensity height, the oil content height, coefficient of friction is low, and copper content is low, and the cost of material is low, and the technology cost is low, can reduce cost 17000 yuan/ton than common explained hereafter Fe-Cu oiliness bearing.

The specific embodiment

The present invention relates to a kind of powder metallurgy Fe-Cu-Sn oil-retaining bearing and production technology thereof, it is to adopt reduction Fe powder (100 order) to be mixed into the copper seeping agent original washing powder mutually with Cu-Sn powder (325 order), sneak into the lubricant stearic acid lithium in use and be molded into the oiliness bearing pressed compact of porosity 20～30%, at 890 ℃ of sintering 20min, at last sintered blank finishing and soaking by lubricating oil can be used then.Concrete prescription is: reduction Fe powder (100 order) 97.5%, Cu-Sn powder (325 order) 2.5%, lithium stearate 8%, wherein Cu:Sn=7:3 in the Cu-Sn alloy.

Claims (2)

1, a kind of powder metallurgy Fe-Cu-Sn oil-retaining bearing is characterized in that: described bearing is made up of following raw materials by weight percent:

-100 orders reduction Fe powder 96.5～98%

-325 order Cu-Sn powder 2～3.5%

Lithium stearate 0.6～1.0%,

Cu: Sn=7 in the Cu-Sn alloy wherein: 2.5～3.5 weight ratios.

2, a kind of production technology of powder metallurgy Fe-Cu-Sn oil-retaining bearing according to claim 1 is characterized in that described technology mainly may further comprise the steps:

Step 1, batching

Take by weighing-100 orders reduction Fe powder ,-325 order Cu-Sn powder and lithium stearates by proportioning;

Step 2, mixing

The material for preparing rotating speed with 19～21r/min in double cone mixer mixes 30～35min, makes compound,

Step 3, pressed compact

Compound is pressed into the oiliness bearing pressed compact under 300Mpa～450Mpa pressure,

Step 4, sintering

Pressed compact at 880～900 ℃ of following sintering 20～30min, is obtained sintered blank,

Step 5, finishing and soaking by lubricating oil.