Grain Refiners
Grain Refiners
Grain refining agent for aluminium and its alloys ensures:-
Consistent properties after heat treatment
Improved mechanical properties
Improved anodised surfaces
Improved machinability
Fine grain structure
Free home cracking
Pressure tightness
How does it work - Normally, light alloys forms coarse , equiaxed and columnar crystals during solidification. The degree of this coarseness of the columnar crystals depends upon the pouring temperature of the metal and the rise and fall set up within the mold.
Such a coarse grained structure can have a contrary influence on heat processes, and sometimes seriously damages rolling, drawing and extrusion operations. A high incident of localised unsoundness results in low tensile strengths and lack of pressure tightness.
Titanium and Boron are very efficient in promoting grain refinement in aluminium alloys. It is observed that they create seeds of titanium boride, titanium carbide, aluminium boride or more complex intermetallic compounds throughout the molten metal. These countless seed lead to the formation of the fine equiaxed grains as the alloy solidifies.
“BALAJI” grain refiner is the most effective and convenient method of adding the necessary quantities of these elements. Several grades are available in tablet form to meet the requirements of any light alloy.
Following are the BALAJI grain refining fluxes:
BT- 211
BP- 201
|
Specifications |
BT-211 |
BP-201 |
|
Base |
Titanium or boron |
Phosphorus |
|
Type suitable for |
Hypo eutectic alloys |
Hyper eutectic alloys |
|
Form |
Tablet |
Tablet |
|
Quantity required |
0.1% to 0.2% of the melt |
0.2% to o.3% of the melt |
Packaging - 50 gms, 250 gms & 500 gms tablets packed in polythelene and in special double moisture protective Al. foil. These tablets are then packed in corrugated boxes of 12.5 and 25 kgs and then finally packed in wooden cases.
Instructions for use-
1. Bring the temperature of the metal to 700C approximately.
2. Turn off furnace and allow the residual furnace heat to increase the metal temperature to about 750C.
3. When the pyrometer indicates that metal temperature is falling, plunge the correct quantity of the grain refiner to the bottom of the melt in one or two stages. Tablets should be plunged with a perforated bell plunger.
4. When all signs of turbulence have ceased the metal should be drossed off before pouring.
