Influence of boron on development of ion-nitrided layers on sintered iron powders

Influence of boron on development of ion-nitrided layers on sintered iron powders

LARGE SCALE PRODUCTION OF STAINLESS STEEL GEARS BY METAL consolidated powders in order to attain the full potential properties of the alloys. A INJE...

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LARGE SCALE PRODUCTION OF STAINLESS STEEL GEARS BY METAL

consolidated powders in order to attain the full potential properties of the alloys. A

INJECTION

study of Mg- (15 or 20) at%& (1 or 3) at%Zn was described. Optimum thermal treatment conditions were established.

MOULDING

M. Enders et al (Schunk Sintermetalltechnik GmbH, Giessen, Germany). The mass production of small, 0.3 and 1 gm, gears in 316L stainless steel was described. The parts were reported to be ready for assembly in an electric toothbrush without any secondary operation. The quality system was outlined.

MECHANICAL PROPERTIES OF MAGNESIUM ALLOY MATRIX PARTICLE REINFORCED

COMPOSITE

K.V. Kainer et al (Zentrum fir Funktionswerkstoffe GmbH, Clausthal-Zellerfeld, Germany).

Light alloys

A study of a Mg alloy, QE22, reinforced with Sic particles was described.

THERMAL STABILITY OF RAPIDLY SOLIDIFIED ALUMINIUM-

Specimens

MOLYBDENUM

size

ALLOY (Ecole

of intermetallic

des

compounds

between Al and transition metals was discussed, powders were prepared by rapid solidification to extend the range of solid solubility and to increase the extent of dispersoid thermal

formation and

during

subsequent

mechanical

AlizMo and the alloys.

Alr,Mo

treatment.

were

identified

in

Lorimer

(University

prepared

from

rapidly

solidified

powder by vacuum hot pressing, extrusion and rolling. Microstructural evolution during processing

was investigated.

precipitates

found

were

regions and heterogeneous

Large

in the deformed

it was suggested that nucleation and growth are

favoured by deformation. PRODUCTION

shape

and

alloy and

of Sic particle

heat

treatment

on

were described.

J.H. Ahn, H. Chung (Korea Inst of Machinery and Metals, Changwon, Korea). Mechanical

alloying

consolidation powders were MA

powders

and

hot

of Ti-Al-(Mn, Cr or V) investigated. Blended and were

compared.

The

MA

powders were reported to have a good combination of strength and ductility

M.

AND PROCESSING

OF A

ALLOY

Hohmann

et

al

(Leybold

Durferrit

GmbH, Erlensee, Germany) A novel atomization method, applied to a BTi

alloy

powder,

was

described.

The

OF

It was reported that Mg-Ca and Mg-Cahigh

pressure

gas

atomization.

by

Powder

characteristics were determined. Powders were consolidated by hot extrusion at 200 to

500°C.

Structure

before and after were described. HEAT

thermal

TREATMENT

SOLIDIFIED

and

properties, treatment,

Porosity

aerospace

gases

in Be materials

and

surfaces degassing. described

water

was

applications

An

OF RAPIDLY

of Burgandy, arising

adsorbed

discussed

on

with

experimental

from

powder

regard study

to was

in which each process stage was

investigated

for its effect on final porosity.

Powders

were

degassed

before

consolidation. Residual porosity could be correlated with models of dynamics of gas bubble formation

MAGNESIUM

It was shown that PM methods could be used

to

produce to

steels

those

of

with

properties

conventional

cast/

wrought alloys. Inert gas atomized, rapidly solidified, powders were used. The improvements attributed to

in properties were elimination of segregation

and optimization of Examples were given.

alloy

composition.

EFFECTOFPHOSPHOROUSON MICROCRACK

INITIATION

AND

FAILURE BEHAVIOUR OF SINTERED STEEL

on

URA du CRNS,

France).

The influence of size and shape of pores static and dynamic properties of

sintered steel was discussed with reference to methods of control reported that addition spheroidization

of pores. It was of P results in

of pores.

0.2’XP

microstructure

were

Steels with

and

and

compared

for

properties.

P

was

A NEW GRADE OF SYNTHETIC GRAPHITE

FOR PM APPLICATION

K.D. Streb Switzerland)

(Lonza

G and

T AG,

Sins,

Problems in the supply of graphite were discussed. It was reported that a new grade of synthetic

graphite

had been developed

for PM use. The graphite powder was shown to have a fine particle size and a narrow size distribution

range,

high

crystallinity

INFLUENCE

OF BORON ON

DEVELOPMENT

OF ION-NITRIDED

LAYERS ON SINTERED

IRON POWDERS

S.Sto1ar-z et al (Inst. of Non-Ferrous Crakow, Poland).

Metals,

The effect of B on the ion-nitriding G. Michot et al (Ecole Nancy, France). Rapid solidification

des Mines de nancy,

RECYCLING

OF STEEL SCRAP FROM

INDUSTRIAL

METAL WORKING

to structures

and the need to use heat treatment

of the

sintered phases

of Mg alloy powders

was discussed with reference

Fe powders found

reported G. Poli

et

al

Bologna, Italy).

and

low ash content.

in solids.

Steels

ALLOYS

C. Verdu et al (GEMPPM Villeurbanne,

process conditions and heat treatment were discussed. Possible

T. Bracconi et al (University Dijon, France).

been produced

Powder

shown to reduce strength and ductility.

K.V. Kainer et al (Zentrum fur Funktionswerkstoffe GmbH, Clausthal-Zellerfeld, Germany). had

0. Grinder, P. Billgren (Soderfors AB, Siiderfors, Sweden).

was reported that the consolidated materials had good properties. Effects of

PHYSICO-CHEMICAL PROCESSES IN THE PM PROCESSING OF BERYLIUM

alloy powders

PROCESSING TO MAKE HIGH PERFORMANCE ALLOYS

without

MAGNESIUM AND MAGNESIUM ALLOYS BY POWDER METALLURGY

Al

USE OF RAPID SOLIDIFICATION

powders were shown to be spherical with few satellites and a mean size of 80 pm. It

were outlined.

AND PROCESSING

formed

predictions of structures and properties possible when used as an addition to Fe based cermets. The predictions were confirmed experimentally. Comparison was made with conventional sintered alloys.

superior

MECHANICAL ALLOYING OF TERNARY TITANIUM-ALUMINIUM ALLOYS

TITANIUM of

Manchester, Manchester, UK) Specimens of A1-8.5wt%Fe-l.2%Si-1.5”%V were

and

ATOMIZATION

ALUMINIUM-IRON-SILICON-VANADIUM G.W.

from

Fe powder

after consolidation.

MICROSTRUCTURAL DEVELOPMENT DURING CONSOLIDATION OF

Y. Wang,

prepared

structure and properties

M.C.S. de Macedo, G Michot Mines de Nancy, France), Formation

were

Sic powders. The influence

Use of carburized

during spark machining of steel in a hydrocarbon was described. The powder characteristics were shown to make

(University

of

Bologna,

compound

to

were

was investigated. BN and Fe,N.

enhance nitride

of The

B was

the

formation

of

layers.

Increased

B

content was shown to be beneficial.

MPR February

1995

41