Effect of specimen size on ductile-brittle transition of recrystallized molybdenum

.Japan). J. Jupun Inst. M&ul.s, Vol 59, No 12, 1995, 1278-1285. (In *Japanese.)

temperature. For specimens 1 mm thick by 1-4 mm wide size had little effect. For

confirmed. optimize

Liquid phase sintering of supersaturated solid solution Fe,- (10 to 33)wt%Cu powders, mechanically alloyed from elemental powders, was investigated. The MA powders were hard and were annealed prior to compaction and sin&ring. Up to 25%Cu, the MA powder was single

specimen thickness 0.3 mm critical temperature was reduced and critical stress lowered slightly.

tensile strength

and high creep resistance.

INTERACTION AND MOLTEN

BETWEEN TUNGSTEN COPPER-SILICON

bodycentred

SINTERED

Cu oozes and

cubic

pl1ase. During

sintering

rearrangement the

attained

of

the

alloy.

The

98”<, density

and

Fe

particle

25%Cu

EFFECT

the

?Fe

J. Takata, h’. Kawai (Kobc

in

0.84,C-O.75”~,Zn stearate endothermic functions

gas

dew point.

when

were

of heating

Fc-Bwt:Cu-

and cooling

Decreased

heating

shrinkage and decrease in caused swelling. Compacts carburizing

and

expanded on cooling. transfer model, to phenomena, is proposed. CONSOLIDATION

sintered

investigated

and carbon these

A. lnoue

PI nl. (Tohoku

.Japan)

J. Japan

Metall.,

Vol

42,

No

40-46.

(In

compacts and 1.6

nanocrystalline powders

GPd

compacts which

are

properties.

Reduction and carburization of W from minerals was investigated and optimum conditions

for

production

established.

The

potential

S.B. Prima

machining

of electrode

et al. Pwoshkwayu

Mc&&~r-

ternary

system

Ti-Nb-Ni

The system is shown to number of pseudo-binary

eutectics and prritectics. The existence 01 a ternary compound, ‘fi:,(i%,Nb),, was not, confirmed.

SIZE ON

by liquid phase sintering, of W heavy alloys are

Applications, high damping

RECRYSTALLIZED Y.Hiraoka, T.IIoshika

BASED

The role of Th and ThO, aditives in enhancing the properties of W base materials

is discussed.

radioactivity Research to including

It is noted that the

of Th develop

presents problems. alternatives to Th,

La or CezO:j dopants,

GRAIN STRUCTURE

et ccl. (Kyushi Inst of Technology, Japan)

J.

Japan

grain and tensile

effects

of

E. Rergmann

(Balzrrs

Int. .I. Refructory

used

3-dimensional delamination, creep

the

and

control

development

Institue.

electron

of

high

Examples

W. Putz et al. (Technical

of the extent

of interlocking

Austria).

from liquid N to ambient

are derived.

is a large

grain

rate where

boundary

RADIO

grain

characteristic there

density

are given.

GROWTH OF DIAMOND IN AN ELECTRODELESS CAPACITIVE FREQUENCY DISCHARGE

bend tests and

current

hybrid processes.

of

in creep

bombardment.,

shape, tests were

prevention

Increase

is discussed which may bc

plasmas. The hot filament can also drive CVD reactions and there is a possibility of

Parameters

stress

IiSA).

1230-1236.

carried nut on fine W wires with respect to fracture. Interlocking grains are considered to have two roles in enhancing creep resistance

to

fracture.

critical

Ltd, Florida,

triode etching and throwing power, activated reactive ion deposition and

boundary

to measure

tools

Mrtwls Hard Muter., Volol

transition

&point

arc

HIGH CURRENT DENSITY PLASMA PROCESSES WITH DIFFERENT VAPOUR SOURCES

PVL) using t,he hot filament

WIRES

(ITniversity of Science,

size on ductile/brittle

penetrators.

with regard to the processes

OF FINE PM

MOLYBDENUM

of

is described.

OF INTERLOCKING

12, 1995,

(In Japanese.)

balance uses, dies

14, No 1:3, 1996, 167.172. OPTIMIZATION

Met&s,

Okayama, dapan). J. Japan Sot. Powder Powder Metull., Vol42, No 1, 1996, 108-l 12.

energy

including capa&y

47.

Kitakyushi, OF

are

Z. Ludynski, W. Novak (OKRIT, Warsaw, Poland.) M&u/. Pmszkow, Vol 28, so 3:4, 1995. 24.28. (In l’olish.)

discussed.

Vol 59, No (In Japanese.)

in MO sheet is described.

alloying

PROCESS ENGINEERING AND PROPERTIES OF TUNGSTEN HEAVY ALLOYS

weights,

TO THORIUM

IN TUNGSTEN

are

for electro-erosion

electrospark

Product,ion, and properties

ALTERNATIVES

WC

was

investigated by metallography, thermal analysis and electron and X-ray probe techniques. contain a

materials and

of

for production

discussed.

yiyu, No 3/4, 1995, 48-54. (In Russian.)

TUNGSTEN

TRANSITION

used

I.V. Sokol et al. Poroshkomyn M&tlhrryiyu. No 3;4, 1995, 114-l 17. (In Kussian.)

Coatings on hardmetal

powders

investigation

RAW TUNGSTEN

PHASE RELATIONSHIPS IN TITANIUMNICKEL-NIOBIUM ALLOYS

The

phase

OF ELECTRODE FROM

1’. Paschen. J. Met&s, F’ol 48, No 1, 1996, 45.

1, 1995,

DUCTILE-BRITTLE

were

pore sizes were smaller in than in vacuum sintered

PRODUCTION MATERIALS MINERALS

liquid

and MO- (c’u.Si).

and kinctir outlined.

OF SPECIMEN

and temperatures

is

Titanium

K. Tanoue

An

It

to analyze

of W- (Cu,Si)

MATERIALS

Molybdenum

specimen

determined.

are used

sintering

ADDITIVES

to have good magnetic

EFFECT

by

above

are discussed.

Sendai,

4.4 Gl’a to make nanocrystalline

amorphous

10%. Kinetics of the reaction

Powdrr

maps are presented for amorphous and nanocrystalline powders. 3 GPa was required to dens@ amorphous powders,

reported

Ta

capsule free HIP or vacuum sintering are described. Shrinkage, porosity and pore were

silicide forms on the W at Si contents Results

of

C11-Si,

It is rc>ported that

Powdrr

Densification of Fe-&-B powders, by hot pressing, was investigated. Uensification

from nanocrystalline

W and molten

University,

SW.

.Japanese.)

dense

sintering

Tungsten

POWDERS

BY HOT PRESSING

make

of

OF AMORPHOUS

IRON-ZIRCONIUM-BORON

from

(In Japanese.)

Investigations

rate caused cooling rate contracted

heating,

Nagoya,

Inst. Mrtuls, \‘ol 59, No

in as

rates and

A new explain

University,

(Nagoya

J. Japun

reported that IIIP material specimens.

(In Japanese.) changes

rt al.

characteristics

J. .Japan SW. Powder Pmc~drr Vol 41, No 12. 1994, 1553-1559.

Dimensional

T. Oki

12, 1996, 12861291.

Steel, Takasago,

between

at 1200 C, was studied.

grain

CONDITIONS ON DIMENSIONAL CHANGE IN IRON BASE COMPACTS

to

Reaction

TANTALUM

Japan).

OF HEATING/COOLING

during

VP. Titov ef al. Poroshkomyn Mr~tullw~iyu, No 3. 4, 1995. 29 32. (In Russian.)

OF POROUS

alloy

size was less than %O/tm even after 1 hour sintering at 1100 C.

Mrtall.,

CHARACTERISTICS

on to the ;/Fe grain boundaries

densifies

Japan)

Tantalum

It is considered possible to the structure for both high

area

is

University, Vienna,

Int. J. Rej+actory

Met&s Hrwd Mater., Vol 14, No 1:‘3, 1996, 173-178. It is reported

that plasma

assisted

MPR October

1996

CVD

39