which two metal can not be welded and why they can not be welded and we need the reason for that? ....etc

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Ferrous metals
Ferrous metals contain iron. Examples are cast iron, mild steel, medium carbon steel, high carbon steel, stainless steel, and high speed steel.
Non-ferrous metals
Non-ferrous metals do not contain iron. Some common non-ferrous metals are aluminium, duralumin, copper, zinc, brass, gilding metal and tin
Joining Metals
Brazing
Welding
Riveting
Machine Nuts & bolts
1.Two pieces of steel sheet are to be brazed. The steel must first be cleaned so that grease and dirt is removed. Wire w ....etc

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i am looking for biosorption heavy metals ppt download. ....etc

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Improving component wear performance through cryogenic treatment
Controlling machine wear is a fundamental function of lubrication. By properly specifying lubricant viscosity, using appropriate modifying additives, and controlling contamination, wear rates can be
minimized to extend equipment life. Cryogenic treatment of tooling steels is a proven technology to increase wear resistance and extend
intervals between component replacements for blades, bits, and machining mills. Recent studies have been conducted on the effects of cryoge ....etc

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CONDUCTIVITY ,FERMI LEVEL ,
MEAN FREE PATH &
RELAXATION TIME
FOR TYPICAL MONO-VALENT METALS
IS SHOWN IN TABLE

The conductivity may be obtained experimentally .
Further we can get by using eqn given below
= ( n*Qe2 * )/me --(1)
but obtained may not be accurate but we will get an idea of magnitude of . In a monovalent metal no of free e- /m3 is equals the no of atoms /m3 . From table we find that relaxation time T is of the order of 10-14 sec .Thus we can say that T is extremely small f ....etc

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Welding

Welding is the process of joining together pieces of metal or metallic parts by bringing them into intimate proximity and heating the place of content to a state of fusion or plasticity

following are the key features of welding:
The welding structures are normally lighter than riveted or bolted structures.
The welding joints provide maximum efficiency, which is not possible in other type of joints.
The addition and alterations can be easily made in the existing structure.
A weld ....etc

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Welding of dissimilar metals
Abstract:
There are many applications where welding constructions are produced from materials of different structures. the same applies to mechanical problems of wear, in a situation of high temperature or other conditions in which different properties required from different parts of the same weld.

This leads to the necessity of connection of dissimilar metals. Between a successful weld dissimilar metals is one that is as strong as the weaker of the two metals being joined, i.e. with sufficient tensile strength an ....etc

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The Structure of Metals



Crystal Structure of Metals

Common crystal structures for metals
Body-centered cubic (BCC) - alpha iron, chromium, molybdenum, tantalum, tungsten, and vanadium.
Face-centered cubic (FCC) - gamma iron, aluminum, copper, nickel, lead, silver, gold and platinum.
Hexagonal close-packed - beryllium, cadmium, cobalt, magnesium, alpha titanium, zinc and zirconium.

Permanent Deformation and Twinning in Crystal
Figure 1.6 (a) Permanent deformation of a single crystal ....etc

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BIOSORPTION OF METALS


SELECTION OF BIOMASS
While choosing the biomass for metal biosorption, its origin is a major factor .

Biomass can come from, activated sludge or fermentation waste from industries like those of food, diary and starch .

organisms coming from their natural habitats are good sources of biomass.

Fast growing organisms that are specifically cultivated for biosorption purposes


TYPES OF BIOMASS

Agricultural products

Seaweeds

Fungi and Yeast

Bacteria
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Prepared by:
Amit B. Mahindrakar

Introduction

This study is motivated by a real problem at the Alang ship-dismantling facility near Bhavnagar in Gujarat. The focus of this study is the paint chip waste which is generated in ship breaking activity. Alang, located 56 Km away from Bhavnagar city in Gujarat, came up as ship breaking site during 1982-83. Hundreds of old ships, after their useful life, are broken at the Alang ship breaking yards without any precaution to protect the environment. Ship breaking and its harmful consequ ....etc

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