CN101187401A - Bearing ball made of cermet - Google Patents

Abstract

A bearing ball is made from ceramet with following weight percentages of nickel powder 15-25%, molybdenum powder 5-15%, and titanium carbide nitride powder as the rest. The process of making the bearing ball comprises mixing the granular powders on a tumbling ball mill by using absolute ethyl alcohol as mixing agent, wherein ball material ratio is 6:1, mixing time is 48h, and granulating 40 meshes by rubbing a sieve, and then pressing pressed compact on a hydraulic press through adopting a steel die with pressed compact density of 2.5-3.0g/cm3, shaping on a cool isostatic press machine with 200MPa of isostatic cool pressing pressure for 2 min, sintering on an atmosphere pressure sintering furnace with 1400-1450 DEG C of sintering temperature for 1-1.5h, using 1.5-3 MPa of the atmosphere pressure. The bearing ball which is made from ceramet is significantly superior to the traditional bearing steel material under the conditions with high speed, high temperature and corrosion, and is obviously superior to silicon nitride ceramics material in regard to manufacturing and processing costs and difficulty respect, which has spreading application space in operating modes with high speed, high temperature and corrosion and the like.

Description

A kind of bearing ball of making by ceramet

Technical field

The invention belongs to the material technology field, specially refer to a kind of bearing ball of making by ceramet.

Background technique

Rolling bearing is that the axle of running and the sliding friction between the axle bed are become rolling friction, thus the mechanical component of a kind of precision of the loss of reducing friction.Rolling bearing generally is made up of inner ring, outer ring, rolling element and retainer.The effect of inner ring is to match with axle, and rotates together with the axis; Matching with bearing support in the outer ring, plays a supportive role; Retainer can make rolling element evenly distribute, and prevents that rolling element from coming off, rotation of guiding rolling element and lubricate; Rolling element is to be evenly distributed between inner ring and the outer ring by retainer, and its shape size and quantity directly affect the usability and the life-span of rolling bearing, and rolling element generally is divided into: roller and ball.

The motion of rolling element is very complicated in the ball bearing work, when rolling element revolves round the sun around bearing axis, also will carry out rotation around self axis, different according to bearing structure and operating condition, the orientation difference of the axis of rotation.Rolling element produces the great centrifugal force that acts on the outer ring in high speed revolution process, can cause bearing fatigue to destroy, the high speed performance of restriction bearing, and rolling element density is the key factor of centrifugal force size under the certain rotating speed of decision.

The bearing ball material requirements has high hardness and contact fatigue strength, good wear resistance and impact toughness.Generally make with the chrome-bearing alloy steel, common used material has GCr15, GCr15SiMn, GCr6, GCr9 etc., and after heat treatment hardness can reach HRC61-65, and density is about 7.8g/cm3.Bearing steel material is used maturation at present, can satisfy general operational requirement.But high speed performance, heat resistance, corrosion resistance are relatively poor.

Silicon nitride ceramic ball is emerging bearing ball scheme, generally adopts gas pressure sintering or HIP sintering technology to make the ball base, mainly adopts hard abrasive material such as diamond to process.Silicon nitride ceramic ball density is low, about 3.2g/cm ³, high speed performance, heat resistance, corrosion resistance are good, but bearing capacity is lower, difficulty of processing is big, cost is high but make.

Summary of the invention

At the problems referred to above, the present invention proposes a kind of bearing ball of making by ceramet, this bearing ball performance under high speed, high temperature, corrosive environment obviously is better than metallic material such as traditional bearing steel, simultaneously again obviously being better than silicon nitride ceramic material aspect manufacturing processing cost and the difficulty, so in operating modes such as high speed, high temperature, corrosion, have application space widely.

For achieving the above object, the present invention has adopted following technological scheme:

The described bearing ball of being made by ceramet is constructed as follows by weight percentage:

Nickel powder 15～25%; Molybdenum powder 5～15%; Surplus is the TiCN powder;

The described bearing ball of making by ceramet above-mentioned constitute under the combination form through mixing granulation → shaping → sintering, each operation is as follows:

I, mixing granulation

Mixing granulation on the roller milling machine, the batch mixing medium is an anhydrous alcohol, and ratio of grinding media to material is 6: 1, and mixing time 48h wipes sieve series grain 40 orders;

II, shaping

On oil hydraulic press, adopt punching block compacting pressed compact, green density 2.5～3.0g/cm ³On cold isostatic press, be shaped isostatic cool pressing pressure 200MPa, time 2min;

III, sintering

Sintering on the gas pressure sintering stove, 1400～1450 ℃ of sintering temperatures, sintering time 1～1.5h, atmosphere pressures 1.5～3MPa.

Because adopt aforesaid technological scheme, the present invention has following superiority:

1, the present invention is between Bearing Steel and silicon nitride material, and the ball base can reach the G5 level after processing, satisfy the design bearing usage requirement.

2, the about 5.7g/cm of ceramet ball density of the present invention ³, be lower than Bearing Steel, so high speed performance, heat resistance, corrosion resistance are apparently higher than Bearing Steel.

3, ceramet ball crushing load of the present invention is not less than 50% of Bearing Steel, and far above 35% level that is higher than silicon nitride ceramics of silicon nitride ball, bearing capacity is apparently higher than silicon nitride ceramic ball.

4, the material powder cost of ceramet ball employing of the present invention is lower than silicon nitride main raw material powder cost, and sintering temperature is lower than the silicon nitride sintering temperature, and difficulty of processing, time and cost are also far below silicon nitride ball.

Embodiment

Embodiment 1

A kind of bearing ball of being made by ceramet constitutes by weight percentage: nickel powder 25%; Molybdenum powder 5%; Surplus is the TiCN powder.

I, mixing granulation

Mixing granulation on the roller milling machine, the batch mixing medium is an anhydrous alcohol, and ratio of grinding media to material is 6: 1, and mixing time 48h wipes sieve series grain 40 orders;

II, shaping

On oil hydraulic press, adopt punching block compacting pressed compact, green density 2.5g/cm ³On cold isostatic press, be shaped isostatic cool pressing pressure 200MPa, time 2min;

III, sintering

Sintering on the gas pressure sintering stove, 1450 ℃ of sintering temperatures, sintering time 1.5h, atmosphere pressures 3MPa.

Embodiment 2

A kind of bearing ball of being made by ceramet constitutes by weight percentage: nickel powder 15%, molybdenum powder 15%; Surplus is the TiCN powder.

I, mixing granulation

Mixing granulation on the roller milling machine, the batch mixing medium is an anhydrous alcohol, and ratio of grinding media to material is 6: 1, and mixing time 48h wipes sieve series grain 40 orders;

II, shaping

On oil hydraulic press, adopt punching block compacting pressed compact, green density 3g/cm ³On cold isostatic press, be shaped isostatic cool pressing pressure 200MPa, time 2min;

III, sintering

Sintering on the gas pressure sintering stove, 1400 ℃ of sintering temperatures, sintering time 1h, atmosphere pressures 1.5MPa.

Embodiment 3

A kind of bearing ball of being made by ceramet constitutes by weight percentage: nickel powder 20%, molybdenum powder 10%; Surplus is the TiCN powder.

I, mixing granulation

Mixing granulation on the roller milling machine, the batch mixing medium is an anhydrous alcohol, and ratio of grinding media to material is 6: 1, and mixing time 48h wipes sieve series grain 40 orders;

II, shaping

On oil hydraulic press, adopt punching block compacting pressed compact, green density 2.8g/cm ³On cold isostatic press, be shaped isostatic cool pressing pressure 200MPa, time 2min;

III, sintering

Sintering on the gas pressure sintering stove, 1420 ℃ of sintering temperatures, sintering time 1.5h, atmosphere pressures 3MPa.

Claims (2)

1. bearing ball of making by ceramet, it is characterized in that: this ceramet is constructed as follows by weight percentage:

Nickel powder 15～25%; Molybdenum powder 5～15%; Surplus is the TiCN powder.

2. the bearing ball of being made by ceramet as claimed in claim 1 is characterized in that: form through mixing granulation → shaping → sintering under above-mentioned formation combination, each operation is as follows:

I, mixing granulation

Mixing granulation on the roller milling machine, the batch mixing medium is an anhydrous alcohol, and ratio of grinding media to material is 6: 1, and mixing time 48h wipes sieve series grain 40 orders;

II, shaping

On oil hydraulic press, adopt punching block compacting pressed compact, green density 2.5～3.0g/cm ³On cold isostatic press, be shaped isostatic cool pressing pressure 200MPa, time 2min;

III, sintering

Sintering on the gas pressure sintering stove, 1400～1450 ℃ of sintering temperatures, sintering time 1～1.5h, atmosphere pressures 1.5～3MPa.