Deformation texture and recrystallisation of tungsten particle in heavy alloy

It is noted that thin sections borosity

create difficulties

of gas-tungsten-arc tion-moulded described.

and residual

in welding.

Use

welding to weld injec-

316L stainless

Application

steel parts is

to parts

for fluid

systems is outlined.

Int. J. Refract. Metals/Hard

Mater, Vol

Mechanical strengthened

of solid

Ta-8 % W-2%Hf

investigated

at elevated

maximum

solutionalloy

stresses

Properties of steel powders prealloyed

600°C.

Tensile tests were at ambient

with chromium and molybdenum

perature

sintered in conventional furnaces K.Kanno et al. (Hagan& Japan KK.,

500°C

Tokyo, Japan.)

180Mpa

Powder/Powder

Metall., Vol4g,

up to llOO°C 1171V.

No 5,

at

300°C

Maximum

up to 85O’C.

this

properties,

are sintered

in continuous

(APT) doped with cobalt Z.Zhang et al. (Royal inst. of Technology, Stockholm,

Sweden.)

to be

Metals/Hard

stress

227-233.

must be reduced because of creep. A creep

Itis reported

mechanism

been

is discussed.

Reduction

by

co-precipitation.

of APT-Co,

in H at 600°C

Titanium

650°C,

was investigated

of Co concentration.

were dispersed

restrict use of Cu and Ni and that sintering

L.M.Berger, W.Gruner. (Fraunhofer

increased particle

of Cr steels may

for Ceramics/Sintered Materials, Dresden, Germany.) Int. J. Refract.

and

considerations

environmental

require

tures. Investigations in conventional

higher tempera-

of sintering

furnaces

The necessary

may

of Cr-Mo

Metals/Hard

are described.

steps for successful

sinter-

Mater, Vol

Development of particle reinforced steel

was investigated.

matrix composites W.S.Lin, Y.Y.Li. (South China University

characterised.

lOvil%N

Industry, Vol II, No 5,

China.) PM

2001, 25-29.

matrix with

composite regard

steel matrix structure Sic,

particle

reinforced

materials material

and properties

Tic,

is reviewed

to reinforcement selection,

TiB,,

Al,O,

steel

processing

and applications. and TiB were stud-

in heavy alloys L.Ekbom, T.Antonsson.

and

to synthesis

Refract. Metals/Hard

carbonitrides.

in presence including

of N.

interme-

382-389.

implants,

Y and Mg-Ca-Al,

phate

powders

Composition,

by hot extrusion.

structures

these are discussed.

shown to have strength greater

and strength

Mg-lat%Zn-2%Y

than

solutions,

with

um arc melted samples.

is

considered

up to Mg

is attributed

was tests

of

conventional

The high strength

intended

Results were compared

and ductility

to

to deformation

at 800°C

to llOO°C.

corrosion diffusion

mouldfor

bio-

investigated

phos-

and without

HCl.

with tests on vacuMicro-porosity

is the

resistance

structures

to establish

effects

hardness

were improved by

of N into the samples.

was

identified.

and sub-grains

heat treatment

formed

as well as recrys-

by grain boundary

migration.

Application of copper-infiltrated tungsten for vacuum high-voltage switch Q.Liang et al. Aerospace China, Vol31,

Mater.Technoi.,

2001, 36-38. In Chinese.

It is reported

that

properties

had been made

of

improvements

in the in W-Cu

sintered

at a high temperature

and infil-

trated and coated

Tantalum

Processing of biocompatible porous titanium and magnesium

Mechanical properties of tantalum at

C.E.Wen et al. Scripta Mater, Vol45,

The W-Cu has a fine and uniform

elevated temperatures. J.R.diStefano, H.E.McCoy. (Oak Ridge

10,2001,1147-1153. A new process

National

Mg metallic foams is reported. These foams

50

Oak Ridge, USA.)

June 2003

for manufacture

A

model is presented.

alloys by pressing W powder in a steel die,

fine grain sizes of 100 to 15Onm.

Laboratory,

heat

and recrystallisa-

texture

cells

were of

by

in buffered

of this alloy. Surface

recrystalli-

dislocation

A (l,l,O)

tallisation

and heat treated

Textures,

on recovery

Dislocation

to be the factor controlling

and corrosion

and

during

of injection-

Int. J. 20, No 5-

heavy alloys were

subjected

tion.

No 5,

In English.

behaviour

potentio-dynamic

gas-atomised

Sintered W-7%Ni-3%F,

treatment

(Nagoya University,

Sweden.)

Mater, Vol

6,2002,375-379.

Y.Xu, H.Nomura.

Metall., Vol4g,

(Royal lnst of

Technology, Stockholm,

determined

It is reported that new Mg alloys, Mg-Znhad been prepared from

effect

sizes were

with

titanium-aluminium-iron alloy

medical

Particle

Deformation texture and

sation

Corrosion

In Japanese.

Co is considered.

Corrosion of injection-moulded

ed Ti-S%Al-2.5%Fe,

200~23-30.

at 650°C

times. Catalytic

with

are discussed.

New high-strength magnesium alloys No 8,

was increased

TiO,

stages leading

A.lnoue. Alutopia

(Japan), Vol31,

size and reduced density.

surface

C are considered

mechanisms,

diate products,

2002,

It is rate,

in Ar-

Nagoya, Japan.)J.Japan Sot.

Magnesium

scale.

reduction

recrystallisation of tungsten particles

was not detected

Reaction

Co increases

were

Two reactions,

Powder/Powder

alloys.

of TiO,,

materials,

ied.

3 times

of

2002,

Co and W

on an atomic

after short reaction

The solid products

oxycarbonitrides

Ti,O, into

reduction

Co and Co with of

Chinese. Researches

No 3,

Specific

at 1300°C to 1800°C for 30 mins,

three reaction

In

Inst,

that

to

with regard to the

20nm to 50nm.

Carbothermal

Technology, Guangzhou,

20,

shown

235-251.

ing are identified.

of

20, No 3, 2002,

that APT, doped with Co had

prepared

effects

that cost

Int. J. Refract.

Mater, Vol

Effect of nitrogen in atmosphere on

of 1150°C,

The

implants.

Tungsten

carbothermal reduction of titanium dioxide

naces at a maximum

fur-

is for biocompatible

Reduction of ammonium paratungstate

It is noted that most PM steels, with additions of Cu, Ni, MO and C to attain good

strength 35Mpa

of 5.3GPa.

tem-

allowable

is reported Above

application

modulus

to

and creep tests at

long term stress intensity

In Japanese.

to 5OOnm in size,

to for a

power

2oo2,444-449.

application

and Young’s

were

temperatures

design

space

to

have open pores 200nm 78% porosity, compressive

properties

establish

J.Japan Sot.

20,

No 5-6, 2002, 381-387.

No

ature sintering

with Cu. High temper-

gives a strong W skeleton.

ture, low gas content of Ti and

between

matrix

and

struc-

and good adhesion surface

Cu.

The

method is shown to reduce part cost.

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