Coating of cemented carbides for turning applications

Coating of cemented carbides for turning applications

FRACTOGRAPHY FRACTURE FERROUS Solid OF FATIGUE SURFACES state investigated IN SINTERED powder MATERL4LS ct al (Kumamoto Kumamoto, and Japan)...

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FRACTOGRAPHY FRACTURE FERROUS

Solid

OF FATIGUE

SURFACES

state

investigated

IN SINTERED

powder

MATERL4LS ct al (Kumamoto

Kumamoto, and

Japan)

Powder

Sot.

Vol

Metallurgy,

1993, 1121-1125.

University,

.J. Japan

49,

various

stress

between

fatigue

steels

was

ratios

on

of

shear

and

intergranular

striations

and

porosity.

surfaces

striated

patterns.

the fracture

high

showed

areas crack

rate

and

surfaces

became

coarser,

with of

solidus temperature by ball

milling

1 pm powders high density.

DYNAMIC

J.A.

College ter.

et

Tempe,

al

(Arizona

Arizona,

Manuf.

Process., Vol 9, No 6, 1994, 1143-1154. The tensile

properties

of Mo-0.5atXHfC were evaluated

a strain rate of 10 “set-’ 2125°C

in vacuum.

hardening dominant reported 1525°C this.

in the range 925 to for

in the temperature range. deformation mechanisms

The are

to

be dislocation

Solid

effective

at

HfC was responsible

and grain

sliding

up to

sliding

above

boundary

solution

hardening

by Re was

up to 1525°C.

BASE ALLOYS

EN. Sheftel, O.A. Bannykh Metalurgy, toT

Moscow,

(Baikov

Russia)

Vol 12, No 5,

304-314.

From investigations the

underlying design

properties

suitable

with

and

with giving

to

for

data

alloys

alloys,

service

and

to

give

at 600

to

1400’ C are discussed

thermodynamics, formed.

TV elements

dispersoids

of

Nb

and phases

group

carbides,

of

1100 to

regard

equilibria

and published

principles

structural 800°C

Inst. of

ht. J. Refrac-

Metals & Hard Materials,

1993-1994,

and

of oxides,

phase

Alloys of Nb 0,N

and

nitrides

C, and

are discussed.

Tungsten SOLID STATE SINTERING TUNGSTEN

and

10 nm

as-sintered

COMPRESSION

TEST ALLOYS

C.H.

Watson

reported

OF

of Tic

the exothermic

reaction

kinetic yields

parameters

UK)

Ma-

CAUSE

OF PORE

and

used

for

of W alloys,

[email protected]

penetrator data,

and

incidence

critical

strain.

and

dispersion

of Test

are discussed.

Coatings CARBIDE

FORMATION

of

Japan)

POWDERS FOR

OF PROTECTIVE

IN

CERMETS

CARBIDE

Powder

WITH

ADDITIONS Inst. of Technology,

J! Japan

Sot.

Vol

Metallurgy,

Powde-r

40,

No

11,

1993, 1131-l 135. (In Japanese). The

formation

Mo,C-Ni particles the

micropores

up

to

were

coated

in TiC

6wtXZrC

It was assumed

was

that the ZrC

with

Zr02

during

and that this was reduced

liquid

during

evolution

of

formation.

sintering

and

result.ed

in

gas

Pores were suppressed

treatment sintering.

of

with

preparation

at

in creep

in the

pore

by heat

1250’ C in vacuum

An increase

ZrC is reported reduction

APPLICATION

of

Ti, C and

and tool

CARBIDE

investigated.

instrumented

and applications

CHROMIUM

between

Hard materiak steels

Narashino,

stress-strain

sensitivity

instability

of

in Fe by means

H. Suzuki et al (Chiba

Military

been

testing

and high density rate

an

had

compression test

given

reactions.

of the endothermic

TITANIUM

Vol 9, No 6, 1994,

that

device

The

(Royal

Shrivenham,

Process.,

before

strength

by

and this is attributed

to

in XC due to reduction

of ZrO,!

STRUCTURE AND PROPERTIES OF SINTERED HIGH SPEED STEEL CONTAINING

COPPER

COATINGS E. V.A.Maslyuk

et al Poroshkovaya

giya, No 8, 1993, 89-91. The use of Cr.& of

protective

possible.

powders

for application

is

The carbide

Metallur-

(In Russian),

coatings

by carburization

Niobium NIOBIUM

highest

of Science,

strain

University,

Mater.

and Mo-Sat’XRe-0.5’XHfC

made from

alloys. shear

State

USA)

die filling.

have good sinterability the

Manqf:

dynamic

AT HIGH TEMPERATURES Luo

benefits

TO TUNGSTEN

Relk,

It is

OF MOLYBDENUM

The dispersion

ZIRCONIUM

drop-weight

A.

which

ductility,

APPLIED

are

endothermic

giving good as-sintered

Compacts

had

Molybdenum STRENGTHENING

the matrix

Powder bulk density is increased

1155-l 161.

AND DISPERSION

examples

and

Fe and

below

had

independent

Some

TiBAl are considered.

can be densified

density and composition.

SOLID SOLUTION

that

fracture, low

were shear

microcracks,

composition

It is reported

discussed. exothermic

range

powder

As stress ratios increased

surfaces

numerous

for

compact

At

rates the surfaces and

in sintered

l/2

Fracture

intergranular

crack

investigated

specimens.

growth

11,

alloy

variables.

was

to the effects of

alloys with W powder in the 1 to 10 urn size

properties.

growth and fracture appearance alloy

No

(In Japanese).

The relationship Fe and

Powder

of W alloys

characteristics,

and process T. Yamaguchi

sintering

with reference

shown

powders

to

be

were made

Dudrova

Vyskumu,

et

al

Kosice,

(I’stav

Materialovehu

Czechslovakia)

Pokroky

Psaskove Metalmggie, No 1, 1994, 14-29. (In Czech). The influence conditions

of >! to lOwt% and process

on the structure

and properties

of a high speed steel, sintered to 99.5’% density, were investigated. Improved

of Cr powder.

Composites

structure

HAVEMETAL

COATING OF CEMENTED CARBIDES FOR TURNING APPLICATIONS

MATRIX COMPOSITES PROVED THEIR WORTH? C. Peel et al Farnborough,

(Defence IJK)

Research

Agency,

World, Vol 3,

Materials

No 1, 1995, 8-9. The matrix

paper

composites

value. The development shown

questions

that

have

whether

metal

proved

t,heir

considerable research effort is noted and MMCs

applications

where

performance

are

are

weight

critical.

that MMCs were oversold

of

and it is

value

saving

in

and/or

and properties

.J. Diblik, Pokroky Psaskove No 1, 1994. 30-3.5. (In Czech). Coatings cermets,

on

for

chemical

Tic-TiN-Ti

cutting

and/or

are discussed properties.

STRUCTURE

in terms

IRON ALUMINIDE

(C,N)

based

applied

physical

deposition

Intermetallic

Metalurgie.

tools,

tribological

It is concluded of the

are reported.

with

by

vapour respect

to

materials

AND PROPERTIES

OF

ALLOYS WITH

time scale for commercial return and that financial support had been withdrawn

ADDITIONS

before this had been achieved.

R.N. Wright et al (Idaho

REACTION

PROCESSING

MATERIALS

INDUSTRY

ing Laboratory, Idaho, USA.) ,I. Materials Science, Vol 28, No 8, 1993, 2040-2048. The effect of quenching Fe:r AI-Cr alloys

IN

HEAVY ALLOYS

OF CHROMIUM National

Engineer-

Labora-

J. Kellie, J. Wood (University of Nottingham, Nottingham, UK) Materials World, Vol 3,

from above 550 C on the microstructure and mechanical properties was investigated for two alloys in the range 2 to 5%Cr. It is

tories, Richmond, Washington, USA) Mater. Manu$ Process., Vol 9, No 6, 1994, 1115. 1126.

No 1, 1995, 10-12. The use of reaction processing to introduce ceramic particles into alloys is

reported that optimum alloys with an elongation brittle fracture mode.

W.E. Gurwell

(Pacific

Northwest

processing yields of 2O’X but with a

MPR April 1995

39