Uses and properties of composite powders made by self propagating synthesis

Uses and properties of composite powders made by self propagating synthesis

Investigations to improve the flowability of magnetically hard powders were described. Results for flow of Ba and Sr ferrites, Sm-Co and Fe-Nd-B powde...

155KB Sizes 0 Downloads 25 Views

Investigations to improve the flowability of magnetically hard powders were described. Results for flow of Ba and Sr ferrites, Sm-Co and Fe-Nd-B powders through l-5 mm orifices were presented. An automatic weigh-feeder, based on the study, was described.

STRUCTURE HOMOGENEITY AND ANNEALING RESPONSE OF MECHANICALLY ALLOYED IRON BASE POWDERS

FORECAST ON PROPERTIES OF RESONANCE TEXTURED MAGNETS

D. Jaeger,

AR.

Warrington,

UK).

J. Vernigorov et al. (Don State Technical University, Rostov-on-Don, Russia). Studies of textures in PM magnetic materials, introduced by the application of constant of fluctuating magnetic fields during processing, were described. Magnetic properties of sintered parts were shown to depend on powder characteristics and process conditions.

materials

deformation

degree

in which

of

particular

freedom.

respect

to for

with

of metal powders,

was discussed with emphasis on control of and methods were microstructure, described. Future possibilities were outlined.

Superalloys BEHAVIOPR

OF A PM NICKEL BASE SUPERALLOY AT 650°C V. Aubourg

(University

et al.

Stbver

et

of Dayton,

(Forschungzentrum

Jiilich

1150°C

and

dilatometry, was reported volume

a

with

Ni AleOs

MPa,

described.

of

superalloy,

and TiBz,

to depend

fraction

densification

based

45-180 was

of

to

continuum

powders

on

are shown

at 950.

using

HIP

Densification

on the type and

of dispersoid.

Shrinkage

contained

the

sponge

and

al.

(Polytecnico

by a wide

were described. B-Si-Fe

and

di Torino,

other

of techniques,

than and

microalloy

Flow

to depend

parameters Hardness

and base

Alloys with B-Si-Fe or Cr-

studied.

reported

range

properties

elements were

more on atomization on

melting

were shown to be related

were

spectroscopy.

The

was shown to be covered

with

possibly Ti oxycarbides,

formed

high

oxide,

up to 4 nm thick,

HSS

at

which

was

temperatures.

reduced

vacuum

heat

by

on high

treatment.

the Ti compound

AlaOs particles

formed.

PROPAGATING

Fe

dominated

the superalloy

On

grew and

OF MADE

BY SELF

SYNTHESIS (University

et al.

of Nottingham,

UK).

It was reported that SHS can be used to prepare fine dispersions of Tic and TiB in Fe and Ni matrices. The use of Tic and TiB wear resistance and other for PM and hardfacing were

HIGH

TEMPERATURE

composition. characteristics to composition.

(Moscow

Iron and Steel Inst.,

Moscow, Russia). The use of SHS to create novel ceramics, and

Structures, including sputtering deposition,

intermetallics properties cutting

targets for

was reviewed.

and tools,

and

a range

applications, magnetic

physical of

vapour

alloys

were

presented.

High alloy steels

SOLIDIFIED

BASE POWDERS et

steels

powders

which

MODIFIED PRODUCED

AND TECHNOLOGICAL OF GAS-ATOMIZED

Investigations of characteristics properties of gas atomized Ni

were

up

were described.

MORPHOLOGY PROPERTIES

alloy

Ti rich compounds,

cermets

and C, by SHS, was

from

on high speed

by Auger

E. Levashov

in an alloy matrix. Types of

made

University

Sweden).

BY

particlulate

formed

OF HIGH

(Chalmers

base

PROPAGATING SYNTHESIS

above 2500°C were reached.

to 85~01% TX

for

A REVIEW OF NOVEL ADVANCED MATERIALS MADE BY SELF

of Nottingham,

Fe-TiC

The sponge material

applications

investigated superalloy

suitable

outlined.

investigated. Ingition was at about 1100°C and the reaction was strongly exothermic.

powder

Fe

to improve applications,

SYNTHESIS

from ferro-Ti

Temperatures

other

Nottingham,

predictions.

(University

be

Gothenburg,

Surface products and

J. Wood

theory.

PRODUCTION OF POWDERS CONTAINING TITANIUM CARBIDE

et al.

to

L. Nyborg, T. Tunberg

was

Powder production/self propagating high temperature synthesis

J. Wood

and

applications.

SURFACE CLEANLINESS ALLOY METAL POWDERS

and

to depend

gave high hardness. Cr was shown to have

USES AND PROPERTIES COMPOSITE POWDERS

Jiilich,

Fe-Cr-YzOs

the theoretical

powders,

GmbH, Jiilich, Germany).

reinforced

(KFA-IWEB,

al.

HIP conditions. The experiments to validate

M. Rosso

UDIMET700,

prior

OF YTTRIA

using

Torino, Italy).

DISPERSOIDS

HIP

powder,

was reported

TITANIUM

of

making up the of these on

experimentally

Densification

hardness

hardfacing

temperature

Germany). HIP densiiication

NICKEL

Investigations

in the

and on the final structures

HIP DENSIFICATION OF NICKEL SUPERALLOY WITH ALUMINA AND

0. Hamed et al.

of the

Nottingham, UK). Production of

Dayton, Ohio, USA). Application of N18, a Ni superalloy, was described with regard to structure and properties. A model of the viscoplastic behaviour of the alloy at 625.675°C and strain rates of 10~‘-10~4sec~1,based on creep tests and electron microscopy was proposed. The results were used to construct equations linking material and energetic parameters.

DIBORIDE

were

electron levels of

inhomogeneities

SELF PROPAGATING

MODEL OF VISCOPLASTIC

and high

is an extra

Production,

consideration

powders

DISPERSION STRENGTHENED IRONCHROMIUM SUPERALLOY BY HIP

and design

there

Technology,

were discussed.

theoretically

applications,

and

consolidation

ogy of Lausanne, Lausanne, Switzerland). Materials with compositionally graded with

alloyed

recrystallization

investigated

reviewed

(ABA

distribution of compounds powder. The effects

(Swiss Federal Inst. of Technol-

heat treatment

High B contents The alloy without

of Technology,

Mechanically

N. Cherradi

were

Jones

characterized by optical microscopy used to show

D.

structures

on

high

PRODUCTION AND APPLICATIONS OF FUNCTIONALLY GRADED MATERIALS

properties,

to depend

but not pressure.

DENSIFICATION

gradients in

Functional

and hardness were reported HIP temperature

HIGH SPEED STEELS FROM RAPIDLY POWDERS

M. Miskovicova et al. (Slovak Academy of Sciences, Kosice, Slovakia). Investigations of structures and cutting properties of sintered M2 HSS were described. Atomized powders with additional Nb, Co and Ti and hot powder extrusion were used. The additional elements were shown to affect crystallization. As-consolidated the alloys were reported to have improved cutting properties in comparison with cast/ wrought materials and compared favourably with polycrystalline diamond tools.

MPR September

1996

39