Title of Invention

A PROCESS FOR THE PRODUCTION OF FERROUS BASED COMPOSITE MATERIALS .

Abstract This invention relates to a process for the preparation of TiC reinceforced ferrous based composite materials from industrial waste.
Full Text FIELD OF THE INVENTION
This invention relates to s process for the production of ferrous
based composite materials.
This invention further relates to a process for the preparation
of TiC reinforced ferrous based composite materials from
industrial waste.
The need for long—lasting component has led to the development of
wear resistant materials. Iron matrix composites have gained
attention essentially as potential wear resistant materials. As
engineering materials, iron and steel are yet to be displaced
from the top slot by the range of polymers/ceramics and other
metals in terms of volume of consumption because of their versa-
tility and low cost. Achievement of the improved wear resistance
by ceramic particle reinforcement is possible and has been
proved. However, it is the economy of producing the composite
that will decide whether it would be able to compete with the
wide range of steels/alloy steels/alloy irons already available
in the market. As there is a constant search for novel and econo-
mical synthesis routes, the various routes of synthesis of Fe-
Tic composite has been evolving over the years gradually. Several
processes are available for the synthesis of these kind of TiC
reinforced ferrous based composites, namely powder metallurgy
technique, carbothermic reduction of ilmenite or rutile in
presence of iron.
Most of the iron-based composites are produced by powder metal-
lurgical route and reinforced with TiC. This product is marketed
under the trade name FERROTIC, TIC ALLOY, FERROTITANIT. The
correlation between microstructure and mechanical properties of
TiC reinforced white iron matrix; composites and hot work tool
steel matrix composites produced by hot isostatic pressing has
been studied. Further, a microstructure development and sintering
kinetics of high-speed steel based composites re-informed with
either TiC or NbC and ball milling assisted low temperature
formation of Fe—TiC composite from ilmenite-csrbon mixture have
also been studied.
The production of composite via powder metallurgy route has its
limitations, eg. mixing of matrix powder and reinforcing particle
must be through in order to achieve uniform dispersion of rein-
forcing phase. Sintering cycle and environment must be chosen
critically to obtain components with near theoretical density,
difficulty af machining or trimming sintered parts because of
high hardness of the materials. One then looks to the other
common route, eg.casting route.
Ceramic particles in metals and alloy were assumed as undesirable
inclusion in past. In the mid-sixties, nickel coated graphite
powders were incorporated in aluminum alloys by injecting the
powders together with argon gas into a molten bath of the alloy
and this marked the beginning of cast metal -- matrix particulate
composites (MMPC). This was followed by specific techniques to
generate cast composites..
The dispersion of TiC in liquid iron alloy was studied and a
qualitative assessment of the condition of dispersion was
established. Terry et al have also tried to develop in—situ Fe —
TiC composite by reaction in liquid iron alloys. In an attempt to
develop Fe-TiC reinforced cast composites through a novel rout;
Galgali et al worked extensively on the production and charac-
terisation of TiC reinforced Fe based composite. The TiC rein-
forced iron based composites were produced by direct carbothermic
reduction of ilmenite ore in a bed of steel scrap contained in a
plasma reactor. Galgali has also produced TiC reinforced steel-
based composite. The TiC reinforced iron based composites cere
produced by direct carbothermic reduction of illmenite ore in a
bed of steel scrap contained in a plasma reactor. Galgali has
also produced TiC reinforced steel—based composites by dissolving
Fe-TiC rich master alloy in liquid steel. This approach was
followed since carbothermic reduction of ilmenite in a graphite
crucible does not permit the preparation of TiC reinforced steel of
based composites by a single smelting operation due to the
inevitable pick up of carbon. However, difficulty arises due to
loss of Ti by oxidation before incorporation into the melt.
However, the need exists to provide more economical synthefi-
routes involving high energy efficiency and low cost oron
production.
OBJECTS OF THE INVENTION
It is therefore en object of this invention to propose a process
for the production of ferrous based composite materials from
industrial wastes which involves in-situ generation of titanium
carbide particles.
It is a further object of this invention to propose a process for
the production of ferrous based composite materials from indus-
trial wastes which is simple, energy efficient and is therefore
economic a 1 .
BRIEF DESCRIPTION OF THE INVENTION
Thus according to this invention is provided a process for the
preparation of ferrous based composite comprising subjecting
industrial waste material to the step of alumino thermic reduc-
tion in the presence of cabron.
In accordance with this invention, the charge needed to synthe-
size the composite consists of siliceous sand, aluminum powder
(stoichiometric amount) and C in the form of cast iron and/or
graphite. The charge is preheated in a pit furnace in a clay
graphite crucible. The crucibles are coated with zircon paint to
prevent carbon pick up. The crucible is removed out of the
furnace when requisite temperature is reached and then the reac-
tion is triggered by adding magnesium turnings. The heat gene-
rated due to aluminothermic reaction is high enough to melt the
charge completely and uniformly. A bottom pouring arrangement is
made so that the liquid metal can be poured directly into a mould
by opening the plug at the bottom of the crucible.
Siliceous sand which is a waste product of the aluminium extrac-
tion plant is a source of Fe2o3 and TiO2. A typical sand

composition comprises, for example, 73.1'/.Fe2o3 , 6.26'/. Al2o3 ,

3.63X TiO2 , 2.5'A Na2O and 3.84% SiO2 by weight with other

impurities, like NiO, Cr2 O3 and V2 O5 to make up the balance. The

sand is rich in Fe2O3 and also contains a substantial amount of

TiO2 .

A typical micrograph of the cast composite is shown in Fig.l of
the accompanying drawings.
Composites produced by this method show impressive wear resis-
tance and thus can find application as wear resistance materials.
The wear resistance property of the composite is better than some
commercially available tool steels and it has the potential as
ambient temperature tool material. This is depicted in Fig.2
which shows the cumulative weight loss in wear of as cast compo-
sites of varying carbon content in steel matrix (designated as
(a>, (b) and > and tool steel material. The wear parameters
are :
(a) Abrasive medium -220 grit SiC paper; (b) Normal load -10.90N;
-1
(c) Sliding speed-1.25 ms
The hardness data of as cast composites is shown in T«ble I,
where materials (a), (b) and (C) are composites of varying carbon
content in steel matrix.
The main advantage of producing Fe based composite via alumino-
thermic reduction is the simplicity of the method by which the
composite can be produced. The heat evolved during aluminothermic:
reduction will melt the charge. Therefore, no expensive experi-
mental set up but only some cheap raw materials are needed to
synthesize the composite- As a result, even a small scale foundry
can produce Fe based composite with improvement in properties
over conventional steel/cast iron castings.
The Fi-TiC composite made via aluminothermic reduction of sili-
ceous sand in presence of carbon has shown very good wear resis-
tance properties. The present study assumes greater significance
in the light of the fact that 'discard' by product is the main
raw material. The composite produced via this method has the
potential of replacing some of the expensive tool materials. The
statement is justified not only due to the properties they
exhibit but also owing to the ease of synthesis and the economy
of the process.
We Claim
1. A process for the preparation of ferrous based composite comprising preheating the
industrial waste material such as herein described to a temperature of upto 900° C to
form a heated charge mixture and subjecting it to the step of alumino thermic
reduction by adding magnesium turnings in the presence of carbon.
2. The process as claimed in claim I, wherein said industrial waste comprises mainly
siliceous sand consisting of oxides of iron, aluminium, titanium, sodium and silicon
with impurities such as oxides of nickel, chromium and vanadium.
3. The process as claimed in claim I, wherein the carbon is in a form selected from cast
iron, graphite, singly or in combination.
4. The process as claimed in claim I, wherein the charge mixture after the alumino
thermic reduction, is poured in the liquid form into moulds for the preparation of
composites.
5. A process for the preparation of ferrous based composite substantially as herein
described and illustrated.
Dated this 12th day of March, 2002
(I. BANERJEE)
of L. S. DAVAR & CO
Applicants' Agent
This invention relates to a process for the preparation of TiC reinceforced
ferrous based composite materials from industrial waste.

Documents:

143-cal-2001-granted-abstract.pdf

143-cal-2001-granted-claims.pdf

143-cal-2001-granted-correspondence.pdf

143-cal-2001-granted-description (complete).pdf

143-cal-2001-granted-form 1.pdf

143-cal-2001-granted-form 18.pdf

143-cal-2001-granted-form 2.pdf

143-cal-2001-granted-form 3.pdf

143-cal-2001-granted-form 5.pdf

143-cal-2001-granted-reply to examination report.pdf

143-cal-2001-granted-specification.pdf


Patent Number 233871
Indian Patent Application Number 143/CAL/2001
PG Journal Number 16/2009
Publication Date 17-Apr-2009
Grant Date 16-Apr-2009
Date of Filing 13-Mar-2001
Name of Patentee INDIAN INSTITUTE OF TECHNOLOGY
Applicant Address INSTITUTE OF KHARAGPUR
Inventors:
# Inventor's Name Inventor's Address
1 DAS DR KARABI INDIAN INSTITUTE OF TECHNOLOGY, KHARAGPUR 721 302
2 BANDYOPADHYAY MR T K INDIAN INSTITUTE OF TECHNOLOGY, KHARAGPUR 721 302
PCT International Classification Number C22C 38/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA