Sintered rare earth permanent magnets

Sintered rare earth permanent magnets

6 Conference Io - - ~ ~ pproceed and sintering It was reported Co, Ni, W, Tic, properties a cermet and mechanical were investigated. method c...

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6

Conference Io -

-

~ ~ pproceed

and sintering

It was reported Co, Ni, W, Tic, properties

a cermet

and mechanical

were investigated. method

counter

material.

severe

wear

Explanations

containing

TiN and WC had been made

by a pin-on-disc

Wear tests were using WC

The transition regimes

as the

from mild to identified.

was

of the wear mechanisms

were

The

opinion

theories,

Mechanical properties of cobalt base matrix alloys for diamond impregnated tools H.Frydrych et al. (University of Mmlng and Metallurgy,

powders,

had been made by gas

The atomized powders were dis-

cracow, Poland.) Mechanical

propertfes

of matrix

alloys for

bonded diamond tools were discussed with ref-

longer valid. Properties ture of additives considered,

was presented.

Zr into the powders. The gels so formed were

Co-Fe and WC-Co

washed, dried, crushed

ples,

which

and fired to powder,

was characterized.

pressed and sintered. tionships

for

the

The

powders were

Structure/property sintered

rela-

materials

Microstructure and prop&ties of titanium carbonitride base ceramics A.Bellos~ et al. (CNR-IRTEC:, Faenza, Italy.) Production

of Ti(C,N)

Starting

WC-5%Co,

base materials

materials

Ni and Co. Structures

erties were investigated positions

were

and

processing

grains of Ti(C,N) (Ti,W)(C,N).

of com-

conditions.

Core

were found to have a rim of

Presence

(Ni,Co)ZTi(W)

was

TiCN,

and prop-

as functions

binder

phase.

Without

Properties correlated with performance

were interpreted

in terms of

teristics under service conditions.

The use of computed in

tomography

a ceramic

in study

was

discussed.

Assumptions

were made concerning

chemical

homogeneity

of the sample and attenuation

of

in the use of rare earth including

Sm-Co,

Zr) and

particularly

Fe, Cu,

alloys,

sintered

types, for a wide range of

and polymer

bonded

was noted. In the case of Nd-Fe-

B the trend is towards higher values of BHIIIPx. of

Comparison

NdZFe14B

was made

was

between

reviewed. NdzFe14B

and PrzFe14B in terms of liquid phase sintering of both

materials.

earth magnets

mm in diameter

costs and performance.

www.metal-Dowder.net

UK.)

applications Sintering

Future

and

solid phase sintering

Starting

from a three-dimena Voronoy-mosaic,

grain boundary movement pore shrinkage

was calculated

for

for pores at grain corners,

grain boundaries

and within

tions. Results were presented

grains.

in

In the

trends

in rare

were discussed with regard to

graphically.

Gravitational effects on compact shaping and structural evolution in liquid phase sintering A.Ugadhaya, R.M.German. Umwrsity, USA.) Liquid phase sintering reference

to

effects

respect of structural

(Pennsyluama

State

was discussed

with

caused stability,

by gravity

during ter-

It was shown that sintering allowed a much wider range

ratios to be used. Experiments

W heavy alloys under micrograv-

ity conditions, were

in

net shaping and

the need for high solids contents

in sintering

permanent

Sm-(Co,

Nd-Fe-B

for grain growth

microstructure,

of solid:liquid

(LJnlversrty ofBirmin&am. Birmqham,

magnets,

and

during

in microgravity

Sintered rare earth permanent magnets

X-rays. It was reported that samples up to 100 had been examined.

sional

model

restrial sintering.

Growth

R.Rudert, T.Rabe. (Federal Inst.for Marenab Research and Testing, Berlin, Germany.)

posed by this gap.

three cases grains are allowed to change posi-

7th International Conference on Sintering. The following Abstracts &of papers pmsented at Sintering 2000, which was held in Ney Delhi, India, in February 2000. For further details cantact Pmf, G.S. Upadbyaya, Dept of Materials and MetaUurgkal Engineering, Indian Institute of Technology, Kanpur %1&&6~ India; tel: +91-512.597624; fax: +91-512-590260, email: gsuWtk.ac.in.

R.Hatis.

Non-destructive porosity determination in materials by computed tomography

porosity

charac-

a

microstructure.

of

was described.

of a metal produced a

binder phase hardness was high and toughness low. Properties

pressing,

were

determined.

described.

made by hot

sam-

It was noted that

factors have given impetus

A computer

ties of Co, Co-Cu-Sn,

proper-

was

there is a gap between

G.Tomandl, P.Varkoly. (Society for Software Systems, Numberg, Germany.)

of the tools. An investi-

containing

struc-

sintering

Threedimensional computer modelling of grain growth and pore shrinkage during sintering

and tribological

solution

ions to introduce

sintering

were said to be more

sintering theory and practice.

gation of mechanical

aqueous

that

models, are no

in activating

although

erence to applications

and Zr(IV)

and

accurately known. The role of electronic

Al and

in an

Al(II1)

was expressed

based on two-particle

pore shrinkage

persed

science

(Indian Inst. of Technology,Kanpur,

G.S.Upadhyaya. l&l.)

to the challenge

of

that hard metal

Issues in sintering technology

techno-economic

given.

M.Rosso et al. (Polirecnrco di Tonno, Tonno, Italy.)

atomization.

that

by a PM route. Tribological

powders

based on Ni-Cr-B-FeC,

of a

G.de Porru. (CNR-IRTEC, Faenza, Italy.)

nickelchromium-boron-alumina-

It was reported

Conterence on

SinteringandRoPMzooo.

Mechanical and wear properties tough cermet material

from papers presented at the iggg EuropeanConferenceon Advances in Hard Materials Production and International Workshop on Diamond Tool Production held in Turin, Italy. in November 1999. For further details contact the EPMA: Old Bank Buildings, Bellstone, Shrewsbury, !%l NU,UK;tel.: [email protected]~;fiW +44-1743-362968; e-mail: [email protected] .

zirconia composite

EURO’PM 99, the 7th International

1 ngs

EURO’PM gg. The following Abstracts are

Synthesis

Featuring selected abstracts from the Proceedings of

during

reported.

macrostructural

space-shuttle

Results evolution

with microgravity

flights,

showed effects

novel

associated

sintering.

Computer-aided microstructural sintering

control of evolution during

I’.C.Kapur et al. (Tata Research, Development and Design Cenrre, Pune, India.) The importance during structure

sintering

of microstructural

control

was

Micro-

is influenced

MPR

emphasized.

by material and process

Februarv

2001

39