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Summary

THE TRADITIONAL TECHNIQUES OF METAL TESTING

INTRODUCTION

Metal testing is the potential activity in the industrial sector.The properties of metals is a decisive factor in the its application.The properties like tensile strength ,ductility,malleability, melting points,hardness etc. are important in the industrial practices.Metal composition is also significant in some applications.In the modern metallurgy there are two types of the testing destructive testing and non destructive testing.In the destructive testing the sample can not be reused again once testing is done.In non destructive testing the sample can be reused again as there is no any potential damage during the testing procedure.India has the rich tradition of Metallurgy.We already knows the icons of Indians Metallurgy like Delhi Iron Pillar ,Bronze statues of Natraja ,Dumascus still etc.Now it is an interesting  part to check how the materials were tested or its properties were identified  in historical period?What properies were important to them ? Some references are there in the books of Rasshastra(रसशास्त्र)   and Shilpashastra (शिल्पशास्त्र).

TESTING OF METALS IN TRADITIONAL SYSTEM

The Sanskrit name for Metal is ‘Loha’.It is derived  from word ‘Luha’(The substance which can be stretched easily (ductile).The traditional books classifies the metals in the following three ways

1) Metals that can be  extracted  in pure forms from mine.

2) Metals that can be obtained after separation and filtration process from ores.

3) Metals  that can be used to purify or alloying purpose.

While selecting the metals for application ,two factors were significant.

I) Ductlity

II) Resistance to corrosion

Also there is the reference of genders of metals. Here we must know the meaning of gender .Gender indicates the properties of the material of substance.

Male Metals :-The metals that have higher values of strength are  called as male metals.For example Iron,Copper etc.

Female Metals :-The metals having lower values  strength are  called as female metals.

Neutral Materials:The Materials like lead were called as neutral metals. Also three states of metals are mentioned in the  Shilpashastra( शिल्पशास्त्र)

1) Prakrutee(प्रकृती  ):-The purified and filtered metal extracted  from ore.It is the natural state of Metal

2) Sanskrutee(संस्कृती ):-When we are making the metals useful for its application by alloying it or with adding some other materials in to it ,then it is called as  Sanskrutee (संस्कृती)

3) Vikrutee(विकृती)-The state of the Metal or Material after the use of several years.The original properties can be deteriorated

EIGHT TECHNIQUES OF THE METAL TESTING

1) अंगपरीक्षा (Anga Pareeksha)-:A  cut section of the metal is taken for inspection.Various marks and other things are identified to decide the properties.

2) रूप (Rupa or Colour)-:The type of metals can be identified by its color or ‘Rupa’.

3) जाती (Jati)-:The properties of the Metal are called as ‘Jati’.

4) नेत्र (Netra):-This is the identification mark done by manufacturers .

5) अरीष्ट(Arishta):-It is the mark done by government officials that indicates the metal purity.

6) भूमी (Bhumee):-It is the mark which indicates the location of the mine.

7) ध्वनी (Sound test):-Metals are making particular sounds when hammered by objects like stick stone.

8) मान (Maan):-The metals are purchased in the different sections like Bar,Strips etc is called as मान  (Maan)

There are 100 types of symbols in case of ‘Anga’.There are 4 types of Rupa.Also 30 Types of Netra and Arishta.For Anga 100 Types are mentioned.

SPARK TESTING IN INDIAN RASSHASTRA

अयस्कांते धुम्रवर्ण सस्यके लोहीता भवेत

वज्रे नानाविधा ज्वाला खसत्वे पांडुरप्रभा

Spark test is now outdated or hardly in use in the age of advanced electronic eqipments.Up to 2010, it was there in Engineering Syllabus.The above Verse mentiones spark test. Meaning of Sanskrit Verse -One can recognize the metal type with the help of spark pattern and color 1)The spark of gold is yelloish 2)The spark of silver is Whitish 3)The spark of copper is Blue 4)The spark of Tin is like color of piegon 5)The spark of Steel is Black 6)The spark of lead is like Smoke color.The above verse is there in the book  ‘Raskamdhenu’(रसकामधेनू)