DESC:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2016

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
TITLE
“PRIMARY MELTING OF TITANIUM ELECTRODE BY MELTING SMALLER ELECTRODE OVER OTHER SMALLER ELECTRODE”

APPLICANT
(a) Name : Mishra Dhatu Nigam Limited
(b) Nationality : Indian
(c) Address : PO Kanchanbagh, Hyderabad, Telangana – 500058, India

The following specification particularly describes the application and the manner in which it is to be performed.
PRIORITY STATEMENT

The present application hereby claims priority from Indian patent application with the application number 202341024925, filed on 31 March 2023, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD OF INVENTION

The present invention relates to a titanium electrode. More particularly, the present invention relates to a method for melting and casting large-scale high-performance titanium electrode from smaller electrodes.

BACKGROUND OF INVENTION
Titanium and titanium alloys have the advantages of high specific strength, good corrosion resistance and high heat resistance, and are widely used in various fields such as aviation and aerospace. After the Cold War, titanium and titanium alloys quickly became military for civilian use, mostly used in aerospace, marine development, chemical facilities and daily light work. At present, titanium alloys are in the stage of transformation from "strategic materials" to "general materials". Although titanium is the fourth-largest resource in the world's mineral resources, it is hopeful to become the third practical metal after iron and aluminum. The development and utilization prospects are very broad.
Traditional small-sized titanium and titanium alloys have low smelting efficiency. The segregation of the chemical composition of the titanium alloy and the undesirable metallurgical structure have an adverse effect on its mechanical properties.
CN107252889A discloses a kind of preparation method of titanium alloy large-sized casting ingot consutrode, using mold cavity, auxiliary stand is placed with mold cavity, mold cavity inner space is divided into N number of lattice by auxiliary stand to be kept off;Titanium sponge, commercial-purity aluminium, intermediate alloy are raw material, carry out dispensing, weighing according to the nominal composition of titanium alloy to be prepared, and obtained mixed material is poured into N number of lattice gear respectively;Auxiliary stand is taken out from mold cavity;Mixed material in mold cavity is disposably pressed into by big substance electrode block using the vertical compacting of short stroke;Step 1 is repeated to step 3, multiple big substance electrode blocks are obtained, and is consutrode by obtained multiple big substance electrode block group welderings.
Increasing application requires large sized titanium ingots. It is not practical to achieve larger size ingot through Plasma Arc Welding as the output will go to forging where it is lead to cracks.
With this background, the present invention discloses a novel preparation method of making large size ingot by melting of smaller electrode over another smaller electrode.

OBJECT OF THE INVENTION
It is an object of the invention to provide a method for producing large sized ingot of Titanium Electrode through primary melting, utilizing a smaller electrode as a base, to enhance efficiency and yield.

SUMMARY OF THE INVENTION
This summary is provided to introduce a selection of concepts, in a simplified format, that are further described in the detailed description of the disclosure. This summary is neither intended to identify key or essential inventive concepts of the disclosure nor is it intended for determining the scope of the disclosure.
A method for manufacturing large ingots of Titanium Electrode by primary melting of Titanium electrode over another smaller electrode, the method comprising selecting titanium sponge of grade 0, Vanadium, Aluminium, and other raw materials depending on the grade; homogeneously mixing the selected materials to form a compact; fusion bonding of said compact, wherein each compact weighs approximately 60 Kgs; welding 72 compacts in a plasma welding chamber with argon shield to form one electrode having a diameter of approximately 750 mm and a weight of approximately 4 tons; melting the said electrode in a Vacuum Arc Remelting (VAR) furnace with a copper crucible, controlling the melting process through two primary currents; melting a 2-ton electrode over the 4-ton electrode obtained in above step during primary melting, thereby obtaining a 6-ton electrode.

DESCRIPTION OF THE INVENTION
The present invention relates to large, premium quality ingots of Titanium Electrode. The present invention more particularly relates to large ingots of Titanium by primary melting of smaller electrode over another electrode wherein the ingots have length greater than 2200 mm.
Titanium and titanium alloys have light weight, high strength, corrosion resistance and extremely excellent mechanical properties. Titanium is extracted as a porous, spongy material, which is referred to as titanium sponge. Titanium sponge is 99.9% pure. The other raw materials include Vanadium, Aluminium depending on the grade.
The technical solution adopted in the present invention include following steps:
Step 1, electrode pressing block:
Choose 0 grade of titanium sponge, V, Al along other raw materials depending on the grade, mix homogeneously, pressed into compact or electrode block;
A compac is made by fusion bonding. Each compac is of approx 60 Kgs.
Step 2: welding electrode:
The compact obtained in step 1 is welded in the plasma welding chamber of argon shield. Herein 72 compacs and joined to form 1 electrode which is approx. 4 ton in weight and 750 diameter.
Step 3, ingot casting melting:
Electrode obtained in step 2 is melted in VAR furnace in copper crucible, wherein melting is controlled through two primary currents.
In order to obtain 6-ton electrode, a 2-ton electrode is melted over 4 ton electrode obtained in step 3 during primary melting. The present invention relates to this technique of melting 2-ton electrode over 4-ton electrode.
The above process is easier said than done because, while melting of 2 ton electrode over 4 ton electrode, the melts enters into the gap between the crucible and ingot. Since the 4 ton is already solidified, the melting of 2-ton electrode affects the stripping of electrode from crucible.
In order to overcome the above challenges, the present invention shall brief on the technique to melt one electrode over another with ease.
Further, the disclosed method may be used to forge 8 ton electrode as well by melting one 4 ton electrode over another 4 ton electrode
,CLAIMS:CLAIMS

We Claim
1. A method for manufacturing large ingots of Titanium Electrode by primary melting of Titanium electrode over another smaller electrode, the method comprising:
a. selecting titanium sponge of grade 0, Vanadium, Aluminium, and other raw materials depending on the grade;
b. homogeneously mixing the selected materials to form a compact;
c. fusion bonding of said compact, wherein each compact weighs approximately 60 Kgs;
d. welding 72 compacts in a plasma welding chamber with argon shield to form one electrode having a diameter of approximately 750 mm and a weight of approximately 4 tons;
e. melting the said electrode in a Vacuum Arc Remelting (VAR) furnace with a copper crucible, controlling the melting process through two primary currents;
f. melting a 2-ton electrode over the 4-ton electrode obtained in above step during primary melting, thereby obtaining a 6-ton electrode.

2. A method as claimed in claim 1, wherein the large ingots of Titanium Electrode have a length greater than 2200 mm.

3. The method as claimed in claims 1, wherein the welding of the compacts is performed in an argon shield plasma welding chamber.

4. The method as claimed in claims 1, wherein the melting process in the VAR furnace is controlled through two primary currents.

5. The method as claimed in claims 1, wherein the melting of the 2-ton electrode over the 4-ton electrode during primary melting poses challenges in electrode stripping due to the gap between the crucible and ingot.