Compound parts by diffusion bonding

characteristic of interface structure and the effect on strength was studied. It was reported that the greater the fractal dimension the greater is the stress concentration and hence the greater is the probability of crack nucleation. SHOCK WAVE COMPACTION OF 2124 ALUMINIUM ALLOY-PARTICULATE SILICON

CARBIDE

I’. Hamakrishnan technoloB,

Bombay,

Investigations and hardness

Institute

of

structures, densities 2124Al alloy-Sic

particulate composites were described. Shock wave consolidation was used and some alloys were hot rolled. Properties and structures were evaluated with regard to process conditions and compared conventionally processed items. FELT METAL

(Inst.

with

media.

This

cooling of products and heat transfer.

deformation summarized

reported.

D. Kovalev, D. Kostogorov (Institute of Structural Macrokinetics, Chernogolovka, Kussia) The role of gas transport in SHS processes was discussed with regard to ignition and combustion conditions in powder materials and investigated experimentally and theoretically. A factor considered was alteration of a solid surface by gas/solid reaction. Process controlling factors

were identified.

REACTIVE

SINTERING

TITANIUM

DIBORIDE

A. Micksi (Swedish Institute for Metals Research, Stockholm, Sweden). Investigations of reactive svrthesis of TiBZ in B-Fe/Ti or B/Fe-Fe/Ti powder mixtures, sintered at a range of temperatures, was described. Sintering was shown to involve a liquid phase mechanism. The liquid phase was transient diminishing as TiBZ formed. Density of only 90% was attained. TiB,

42

MPR October

1996

of combustion synthesis A problem arose from

were presented.

Inst., Moscow,

Studies of the application of PM to make plain hearings in difficult-to-make materials were described. Effects of process variations were investigated. Cu and Fe base alloys with additions of oxides and carbides were used and characterized with regard to process conditions. DEVELOPMENT OF GRADED MATERIAL BY PULSE DISCHARGE RECICTANCE

CONSOLIDATION

H. Kimura, T. Kazutoshi

(Koyo Seiko Co Ltd,

Osaka, Japan). A method for consolidation of compositionally graded materials by pulsed electric discharge resistance was described. The technique a temperature profile over the composition gradient by use of a shaped die. An example in which a temperature difference of 700‘C across a 7 mm five layered structure from an aluminide to a ceramic was given. Properties thorough the section were described.

COATINGS

D. Shtansky e:t al. (Moscow

Steel and Alloys

COMPOUND

PARTS

BY DIFFUSION

BONDING

Russia).

Hard films based on Ti-B-N, Ti-C-N and Ti-MO-C-N, deposited by sputtering, were characterized. It was shown that the films had mostly single phase nanocrystalline structures which in some cases had a high Ar content of 2at’%. Ar occupied Ti lattice sites. Film properties were affected by deposition wear

parameters.

resistance

High hardness

and

good

CHARACTERISTICS CARBONITRIDE N. Antonova Institute, Effects synthesis powders evolution Effects

of

and were

OF TITANIUM

et al. (Moscow of

acoustic

of

Ti(C,N,)

Steel and Alloys

wave

energy

on

from

elemental

were investigated.

combustion

and

structure

mechanisms

were

proposed.

powder

characteristics

were

described. GRADIENT

STRUCTURE

INFILTRATION

FORMATION

OF SHS PRODUCTS

V. Gorovoi, A. Pitylin (Institute Macrokinetics, Chernogolovka, structure described. exothermic penetrates

of

formation

of

of Structural Russia). a

gradient

of TiC on a Ni substrate were The Ni is melted by the reaction the Tic.

between Ti and C and

OF COMPOSITE

Seilstorfer

(Seilstorfer

MATERIALS

OPERATED

DENSITY

V. Varavka

et

(Don

al.

State

University, Rostov-onDon, The possibility with

density

direction to

WITH

GRADIENTS

of forming thin wall tubes gradients

in

was investigated

the

PM

techniques

the

with used

differential

densities.

examined

microscopically

measured

Technical

Russia). radial

reference to

obtain

The structures

as a function

and

were

density

of depth.

Spray forming REACTIVE

ATOMIZATION

AND

DEPOSITION PROCESSING NICKEL ALUMINIDE E. Lavernia

et al.

(University

It was reported

OF TRI-

of California,

Ni,&l. Microstructures regard PLAIN

to 0 content

Energetics

of

numerically cooling (Don State Technical

University, Rostov-on-Don,

Russia).

that a novel technique

had been used to prepare

BEARINGS K. Shugay, V. Varavka

H.

GmhH, Haag-Winden, Germany). It was reported that gaseous HIP could he used to diffusion bond areas of differing materials in both new and used parts. The materials to he bonded could be solid or powder. Properties, particularly thermal expansion, strength and possible interactions between materials were considered. The need for further development work was emphasized.

USA).

Functional gradients in materials MANUFACTURE

P. Duerdoth,

PENETRATED

Russia).

by combustion

Two-stage

adhesion

SYNTHESIS

Moscow,

Studies OF IRON-

describing

TARGETS IN PVD OF MULTICOMPONENT

catalysts

OF CHEMICAL GAS IN SHS PROCESSES

models

and extrusion

WEAR RESISTANT

MECHANISM TRANSPORT

flow of compressible

in SHS compaction were and solutions for uniaxial

A.G. Kostornov et ml. (Institute for Problems of Materials Science, Kiev, Ukraine). A method of making porous, fibrous Ni materials was described. The process is based on filling a polymeric felt material with a solution of metallic salts. The salts are reduced to metal and the polymer is thermally decomposed. Up to 981:) porosity was attained. The mateials had high permeability and good mechanical properties. It was considered important that there was no closed porosity. Applications as filters and substrates for

self

Physics,

dependence of density on applied pressure. Models of thermal processes and

COMPOSITE DEPOSITION

were suggested.

Chemical

extended

compression

MATERIALS

Powder production and propagating high temperature synthesis

of

OF SHS

Chernogolovka, Russia). Rheodynamit: models were used to study deformation of powder materials during SHS and to analyze

India).

of of

RHEODYNAMIC THEORY POWDER COMPACTION L. Stelmakh

COMPOSITES

et a(. (Indian

precipitates were 2 to 5pm in size and compacts with 25 to 5Ovol’X TiB2 were made. Effects of process conditions were described.

of

the

dispersed with

in the atomizing

gas.

process

and discussed the

oxide

were examined

alloy

were

studied

with respect

to

droplets.

Good

calculated

and

agreement

between

experimental

results is reported.