FIELD OF THE INVENTION:
This invention relates to an improved process for analysis of Babbitt
metals.
This invention further relates to an improved process for easy, faster and
accurate analysis of Babbitt metals by ICP, via the formation of highly
soluble tartarate salts.
BACKGROUND OF THE INVENTION:
Babbitt is a white metal alloy that is used as the lining for bearing shells
of cast iron, steel and bronze.
Babbitt was first used as a white metal alloy that showed excellent
bearing properties. Since then, the name Babbitt has been used for other
alloys involving similar ingredients. Babbitt's shows an almost
unsurpassed combination of compatibility, conformability, and
embedability. They easily adapt their shapes to conform to the bearing
shaft and will hold a lubricant film. Foreign matter not carried away by
the lubrication is embedded below the surface and rendered harmless.
These characteristics are due to Babbitt's hard/soft composition. Tin
Babbitt's, for example, consist of a relatively soft, solid matrix of tin in
which are distributed hard cooper-tin needles and tin-antimony cuboids.

This provides for "good run-in" which means the bearing will absorb a
lubricant on the surface and hold the lubricant film.
Two basic types of Babbitt are : (1) high-tin alloys (2) high-lead alloys.
Both are relatively low melting materials consisting of hard compound in
a soft matrix. The compounds found in each group are similar; it is in
the composition and properties of the matrix that they differ. High-tin
Babbitt is used for high unit load and high operating temperatures. They
display excellent corrosion resistance, easy bonding, and fewer
tendencies for segregation and welding. They are preferred for use under
steady load conditions in steam and gas turbines, electric motors,
blowers, and pumps.
Lead-based Babbitt is prone to separate into elemental lead and tin and
has a lower thermal conductivity. Users of Babbitt ingot melt the metal in
iron kettles from which they can ladle or pump the molten alloy. The
bearing shell or backing is pre-coated with tin for tin-base bearings or
with lead-tin for lead-base bearings. While the coating is still molten, the
white metal is cast onto the backing and allowed to solidify from the

bond inward. This prevents contraction cavities at the bond and restricts
the growth of intermetallic compounds at the interface between the
bearing shell and the Babbitt. The lining is then machined to a mirror-
bright finish and specified thickness.
Therefore, analysis of Babbitt's is essential during process of making
white metal.
OBJECTS OF THE INVENTION:
It is therefore an object of this invention to propose a process for the
analysis of Babbitt metal, which is simple.
It is a further object of this invention to propose a process for the
analysis of Babbitt metal, which uses simple equipments and chemicals,
and is cost-effective.
Another object of this invention is to propose of a process for the analysis
of Babbitt metal, which is fast and accurate.
BRIEF DESCRIPTION OF THE INVENTION:
Thus according to this invention is provided a process for the analysis of
Babbitt metals which comprises adding 1:1 hydrochloric acid and dt-

tartaric acid to a sample of the Babbitt metal to form a mixture followed
by heating the mixture till complete dissolution; cooling and transferring
into volumetric flasks and adding a 1000 ppm cobalt solution thereto as
a reference solution and making up the volume with hydrochloric acid, to
obtain a solution of the Babbitt metal. A standard solution is prepared by
dissolving dt-tartaric acid in 1:1 hydrochloric acid, adding a 1000 ppm
cobalt solution and the volume is made up using hydrochloric acid.
The solution of Babbitt metal thus prepared is subjected to spectro
photometric analysis using inductively coupled plasma atomic emission
spectroscopy, commonly referred to as ICP. This plasma power, nebulizer
flow auxiliary flow, torch position and other parameters of the
spectrophotometer are adjusted in accordance with the requirements of
the process.
It is essential to choose the operational parameters of ICP. The plasma
power is 1400 watt, the nebuliser flow is 8 to 8.5 lit/min (cross flow) and
the auxiliary flow is 2 lit/min. The torch position is 0.4 mm (vertical) and
4.8mm (horizontal). The integration time is selected at about 45 seconds.
The plasma is allowed to stabilize over 39 minutes.
The invention will now be explained in greater detail with the help of the
following non-limiting examples.

Examples:
Experiment:
Analysis of Lead Base Babbitt metal by ICP
Calibration solution Preparation:
0.05, 01 85 0.15 gm of B.C.S. samples of Lead base White metal (177/2)
are taken in three 250 ml beakers and 100 ml 1:1 hydrochloric acid and
5.0 gm of dl- Tartaric are added to it. The Beakers are placed over hot
plate in low heat until complete dissolution. After completion of
dissolution, the beakers are cooled and the contents are transferred into
250 ml volumetric flask. 10 ml of 1000PPM cobalt solution is added as a
reference solution and volume is made up to the mark by 1:1
hydrochloric acid.
Concentration calculation in PPM from weight dilution.
Wave length used
i) Pb: 220.35lnm & 405.780 nm
ii) As: 197.262nm
iii) Bi:206.170nm
iv) Cu:224.396nm & 327.396nm
v) Ni:221.648nm
vi) Sb: 187.115nm 85 206.833nm
vii) Sn:181.134nm&242.949nm

Standard Calibration Solutions:
Table: 1. Concentration of different constituents of certified white metal
standard (177/2)

Reference Solution: Add 10 ml of 1000 PPM cobalt solution to each flask
equivalent to 40 PPM.

Recalibration standard: Std. 1 and Std 4
Solution Preparation for measure sample:
01 gm Lead base sample is taken in a 250ml beaker and 100 ml 1:1
hydrochloric acid and 5.0 gm of dl-Tartaric acid is added to it. Beaker is
placed over hot plate in low heat until complete dissolution. After
completion of dissolution, the contents are cooled and transferred into
250 ml volumetric flask, added 10 ml of 1000 PPM cobalt solution as a
reference solution and volume is made up to the mark by 1:1
hydrochloric acid.
Results


Analysis of Tin Base Babbitt metal by ICP
Calibration solution Preparation:
0.05, 01 85 0.15 gm of B.C.S. samples of Tin base White rnetal (178/2)
are taken in three 250 ml beakers and 100 ml 1:1 hydrochloric acid and
5.0 gm of dl- Tartaric are added. The Beakers are placed over hot plate in
low heat until complete dissolution. After completion of dissolution, the
beakers are cooled and transferred into 250 ml volumetric flask, add 10
ml of 1000 PPM cobalt solution is added as a reference solution and
volume is made up to the mark by 1:1 hydrochloric acid.
Concentration Calculation in PPM from weight dilution.
Wave length used
i) Pb: 220.351nm& 283.204
ii) As: 228.312nm
iii) Bi: 109.241nm & 223.061nm
iv) Cu:224.700nm 85 327.754nm
v) Ni:221.648nm
vi) Sb: 206.833nm
vii) Sn:181.134nm & 189.991nm
viii) Zn:202.548nm & 213.856nm
ix) Cd:21.438nm & 228.802nm
x) Fe: 259.940nm 8& 238.204nm

Standard calibration solutions
Table 2: Concentration of different: constituents of certified white
metal standard (178/2)

Reference Solution:Add 10 ml of 1000 PPM cobalt solution to each flask
equivalent to 40 PPM.

Recalibration standard:Std. 1 and Std 4
Solution Preparation for measure sample:
Taken 01 gm Lead base sample in a 250 ml beaker and added 100 ml 1:1
hydrochloric acid and 5.0 gm of dl-Tartaric acid. Beaker is placed over
hot plate in low heat until complete dissolution. After completion of
dissolution, the contents are cooled and transferred into 250 ml
volumetric flask, added 10 ml of 1000 PPM cobalt solution is added as a
reference solution and volume is made up to the mark by 1:1
hydrochloric acid.
Results


NB:Standard sample taken for Calibration solution: British Chemical
Standard, White metal No: 177/2 (Lead Base) and 178/2 Tin base)
Concentrations (in ppm) of different constituents are calculated by
weight dilution method with help formula given below:


WE CLAIM:
1. A process for the analysis of Babbitt metals comprising the steps of
preparing a solution of hydrochloric acid and dltartaric acid to a
sample of the Babbitt metal to form a mixture, followed by heating
the mixture for complete dissolution, to form a solution;
cooling the solution,
adding a cobalt solution thereto and making up to the required
volume using hydrochloric acid, to obtain the Babbitt metal
solution,
subjecting the Babbitt metal solution to spectrophotometric
analysis using inductively coupled plasma atomic emission
spectroscopy (ICP), with the nebuliser flow at 8 to 8.5 lit/min, the
auxiliary flow 2 lit/min, and the torch position at 0.4 m vertical
and 4.8 mm horizontal.
2. The process as claimed in claim 1, wherein the concentration of
the cobalt solution is 1000 ppm.
3. The process as claimed in claim 1, wherein about 10 ml cobalt
solution is added to the Babbitt metal solution.

This invention relates to a process for the analysis of Babbitt metals comprising the steps of preparing a solution of hydrochloric
acid and dltartaric acid to a sample of the Babbitt metal to form a mixture, followed by heating the mixture for complete dissolution,
to form a solution;
cooling the solution,
adding a cobalt solution thereto and making up to the required volume using hydrochloric acid, to obtain the Babbitt metal solution,
subjecting the Babbitt metal solution to spectrophotometric analysis using inductively coupled plasma atomic emission spectroscopy (ICP), with the nebuliser flow at 8 to 8.5 lit/min, the auxiliary flow 2 lit/min, and the torch position at 0.4 m vertical and 4.8 mm horizontal.