GMAW is Gas Metal Arc welding or MIG or Metal Inert Gas Welding. This  is most popular welding process among Modern Welding Technologies.

Article Coverage – GMAW:

1. What is MIG Welding?
2. MIG Welding Equipments.
3. Working principle of MIG welding.
4. Modes of GMAW Transfer.
5. Shielding Gas and Properties.
6. Gasless GMAW.
7. Polarity of Electrodes for GMAW.
8. MAG Welding – Metal Active Gas Welding.
9. TIG Welding – MIG Welding Comparison.
10. MIG Welding Advantages and Limitations.
11. MIG Welding Applications.

What is MIG Welding?

MIG welding or Gas Metal Arc Welding or GMAW is welding process in which fusion of workpiece and filler metal occurs due to heat generated by electric arc under the shield of inert gas. Here, filler metal is endless metal wire which itself acts as electrode.

MIG Welding Equipments:

DC Power Source

MIG welding needs constant voltage DC power source.

Wire Feeder

This is constant speed wire feeder that feeds the wire to welding gun as it is consumed for welding. This is the element that makes MIG welding far efficient and better than stick welding.

Welding Gun

Welding gun holds electrode, provides ports for fitting gas hoses and eases the welding process with its ergonomic shape.

Gas Cylinder and Hoses

Unlike Gas Welding, here gas cylinder contains non-explosive inert gas. Hoses are needed for carrying gas from cylinder to welding gun.

Working Principle of MIG Welding

Electrode gets heated by electric current and melts. Molten electrode is used as filler for welding process. To continue this process in loop, a reel of consumable electrode wire is used. Weld puddle is always covered under shield of inert gas to avoid any inclusion of atmospheric gases in the weld.

GMAW Transfer Modes:

What is GMAW Transfer Mode?

It is the mode by which electrode metal wire transfers from gun to weld puddle and settle to complete the join.

1. Short Circuit Transfer Mode.
2. Globular Transfer Mode.
3. Spray Arc Transfer Mode.

Factors Affecting GMAW Transfer Mode:

• Shielding gas.
• Voltage.
• Current.
• Electrode diameter.
• Feed speed of electrode wire.

Short Circuit Transfer Mode

In short-circuit transfer, electrode directly comes in contact with workpiece and electrode tip gets heated. Then molten tip detaches and becomes part of weld. This cycle repeats many times in each second to complete the welding.

Globular Transfer Mode

Electrode melts and a droplet of molten metal gets collected at tip of electrode. This drop falls into puddle by gravity. It uses CO2 – carbon-dioxide as shielding gas.

Spray Arc Transfer Mode

This is most desirable mode of GMAW transfer. Spray of molten metal runs from tip of electrode to puddle along the welding arc.

Shielding Gas and Properties for MIG Welding

Shielding gas protects the weld quality by isolating the weld from atmospheric contents like oxygen, dust etc. Most desirable gas for MIG welding is Argon. It is heavy and covers weld puddle properly. Apart from Argon, Helium, Carbon dioxide and mixture of CO2 and Argon are used.

Gasless GMAW – MIG Welding:

GMAW is Gas Metal Arc Welding. Name GMAW denotes that gas must be used in the process.

Purpose of using gas in GMAW is to shield weld puddle. This purpose can be solved by using flux coated electrode reel. When arc is stuck between electrode and workpiece, flux gets converted into gas which covers the weld puddle. So, no need to have shielding gas, hence called gasless GMAW.

Electrode Polarity for GMAW:

Normal GMAW: Electrode positive.

Gasless GMAW: Electrode negative.

MAG – MIG Welding Comparison

MAG is Metal Active Gas Welding.

In MIG welding, shielding gas does not take any part in welding and that is necessary too. But in MAG, gas participation is expected to complete the weld. Depending upon the workpiece, electrode composition Active Gas can be used.

TIG – MIG Welding Comparison

TIG welding is Tungsten Inert Gas Welding or GTAW.

Major difference between TIG and MIG welding is electrode. TIG uses, non consumable tungsten electrode. Tungsten has very high melting point. So, arc formed between Tungsten electrode and work generates the heat enough to melt work and filler rod.

Apart from that, TIG welding is considered to be one of most difficult welding process while MIG is considered to be easiest.

Advantages and Disadvantages of MIG Welding:

MIG Welding Applications:

• Being low-cost, easy and wide material coverage MIG welding is very useful in Automotive industry.
• For any workshop, MIG welding is equally important as that of Lathe Machine or Drilling Machine.
• Pipe welding.
• Robotic welding. MIG welding can be totally automated to produce the output at very high rate and quality.

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Related posts:

1. TIG Welding – Gas Tungsten Arc Welding [GTAW]
2. Modern Welding Technology
3. Notes on Gas Welding

GTAW (Gas Tungsten Arc Welding) is also called as TIG Welding (Tungsten Inert Gas Welding). It comes under Fusion Welding section.

TIG Welding Equipments:

Figure shows the basic setup for TIG welding.

1. Welding Gun: It is the assembly that loads electrode, electric connections and ports for gas connecting tubes.
2. Power Supply: DC or AC power supply.
3. Gas Cylinder and Connecting Tubes: Gas cylinder for shielding gas supply (argon, helium etc.). Connecting tubes for carrying gas from cylinder to welding gun.
4. Tungsten Electrode: Arc is created between workpiece and tungsten electrode. Tungsten have the highest melting point of all of the metals hence tungsten is used.
5. Filler Rod: Depending upon type of welded joint filler rod may be needed or not. Generally made of base metal.

TIG Welding Operation Overview:

TIG welding is performed in very similar manner as that of other arc welding processes. DC or AC power supply is used. Arc is stuck between workpiece and electrode under the cover of shielding gas like argon, helium or similar combination etc. This results in heating of the workpiece and the electrode. Temperature of 35000 F or 19000 C can be achieved. As electrode is made of tungsten it does not melt but workpiece does. Molten metal pool is created at welding zone. Depending upon the need and type of the welded joint, filler metal can be used. Care must be taken to keep the tip of the filler metal within the shield of the gas. If molten tip comes out of the gas then atmospheric contents may contaminate the metal causing contaminated welded joint.

Arc Strike-Start Methods for TIG Welding:

1. Scratch Start: Easy but contaminates the electrode.
2. Touch Start or Lift Arc: Best method but needs additional equipment to control the electric properties.
3. High Frequency Generator: Good method but can cause harm to workpiece having some electric circuitry on board.

Power Supply – DC, AC, Electrode Polarity:

GTAW with AC – Alternating Current:

Current flow occurs due to flow of electrons in the conductor. In AC power source this current keeps on changing its direction continuously. This switching of direction of current per second is called as frequency, which is measured in Hz (Hertz). Most of places in world this is kept at 50Hz or 60Hz.

AC is can be used for TIG welding operation. More is the frequency, better is the arc stability and focus.

Round tip electrode is used for TIG when using AC.

GTAW with DC – Direct Current:

Direct current is simpler to understand. Here, flow of electrons does not change its direction. So, there is no term called frequency in direct current. But there is another term comes in picture, Polarity.

Electrode Negative or Straight Polarity:

• Negative end of power supply is connected to electrode.
• Flow of positive ions is from workpiece to electrode.
• Arc is stable.
• More, about 70%, heat is concentrated on workpiece.
• Deeper penetration is achieved.

Electrode Positive or Reverse Polarity:

• Positive end of power supply is connected to electrode.
• Arc goes erratic at times.
• More, about 70%, heat is concentrated on electrode.
• Longer electrode is needed.
• Penetration is not deep as straight polarity.
• Positive ions flow from electrode to workpiece. These ions can break the oxide coating on non ferrous materials giving cleaning of work.
• Has excellent oxide cleansing property of non ferrous materials like aluminum.

Shielding Gas:

Shielding gas shields the other atmospheric gases, mainly oxygen and impurities, from being the part of weld. Inert gas does not react with either electrode or work even at very high temperatures.

When arc is stuck, circuit completes through the gap between electrode and work. So, shielding gas must have very good ionization capabilities.

Argon and Helium are mostly used in TIG. But argon has excellent properties for this process. It is heavier than air. It ionizes faster than helium.

Advantages:

1. Arc welding is good at making strong joints. But it falls short on some very strong or reactive metals such as stainless steel, bronze, brass, aluminum, magnesium, titanium etc. TIG welding works very well with all these metals.
2. No harmful fumes are produced.
3. Heat affected zone is small or lesser.
4. Here inert gas (which is totally transparent) shields atmospheric gases from hot metals very well so flux is less needed. This allows welder to see the actual welding zone and welding with very high accuracy can be achieved.
5. Quality of welds can be controlled through electric supply. DC, AC both can be used. When using DC, Electrode polarity can be swapped which changes welds quality.
6. Process can be automated.
7. Gases used here are not explosive, as they are in gas welding operations.

Disadvantages/Limitations:

1. Hard to learn. Skilled welder needed for crucial job.
2. Care must be taken to keep filler rod within the shield of gas. If it is taken out then atmosphere may contaminate the tip of rod which is in molten state.
3. Very bright arc rays are produced. Ultraviolet light is also emitted from arc. This also results in ozone and NOx formation. Proper care must be taken to cope up with these.
4. Due to ozone, NOx formation and shield gas itself it may be dangerous to work in compact areas. Ventilation is must to avoid potential hazards.

Where To Go From Here:

1. TIG Welding Resources From Miller

2. TIG Welding on Wikipedia

3. Check MIG Welding Article

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Related posts:

1. Notes on Gas Welding
2. Modern Welding Technology

What is VoIP?

VoIP is Voice Over Internet Protocol. This is great tool for voice communication over long distance, over internet.

How VoIP works – Step by Step

VoIP is sending voice from one end, traveling through network and retrieving that voice signal on the other end.

1. In a properly set VoIP system, a user speaks and this voice signal is captured by input device which is normal looking but an IP phone. This device is connected to or is an ATA(Analogue Telephone Adapter) in the system.
2. ATA then transmits the signal to NETWORK.
3. On the other side, at other user this signal is captured by other system.
4. That digital signal is converted into analogue, i.e. voice that can be heard.

What is ATA?

All the best voip services needs this. ATA  long-form is Analogue Telephone Adapter. It’s a device that converts simple analogue voice message to digital signal that can be passed over network and convert back to analogue voice message.

For a Concept, What VoIP Takes For Minimum?

For short, a VoIP set up needs 4 things:

1. 2 sets of Microphones and Speakers: These are used to send and receive the voice messages.
2. Software to convert analogue to digital and vice verse: This software will take input from input devices like microphone and convert that signal to digital. On the other end, digital signal is processed back to analogue by the same software.
3. High speed network, minimum like DSL: Network is connecting link. It will simply provide path for digital signal from one end to other.

Advantages of VoIP:

• It does not need separate connection for Voice and Data.
• Communication can be made literally for free or very low cost.
• VoIP can handle more than one VoIP calls over same broadband network.

Where to Go From Here:

For more information on VoIP, check below.

1. Consumer Rankings.

2. VoIP on Wiki.

3. How it Works – VoIP.

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Welding Technology:

Welding is extremely useful and popular industrial process. Welding Technology is not only used in industries, but they are also used in small works and things needed for day to day life. Here, in this article, we start with some basics of welding. Through this series, we will move towards details of Welding Technology.

Welding:

Welding is joining process. It is mainly used on thermoplastic materials. Thermoplastic means, the material which gets plastic when heated and becomes solid after cooling is done. So, Welding is mainly meant for Metals.

Welding, joining of metal parts, is achieved through different means. Depending on these methods, welding can be divided into 4 main types.

• Electric Resistance Welding (ERW).
• Fusion Welding.
• Pressure Welding also called as Forge Welding.
• Brazing, Soldering.

Important Types of Welding:

1. Electric Resistance Welding (ERW):

Electric Resistance Welding (ERW) is achieved by passing high current through workpiece. Two parts to be joined are held connected by holding assembly. Current which passes through the body of parts faces maximum resistance at the point of contact. Resistance increases the temperature at that point and metal melts at that point. Joining of material is achieved after cooling of this spot.

Spot Welding is one of popular implementation of Resistance Welding. Spot welding is not fluid proof welding but resistance welding can be used for making fluid proof parts like metal tanks. For that, holding electrodes are replaced by roller electrodes, also called as Seam Welding.

2. Fusion Welding:

Fusion, name explains the welding. Fusion means melting. In this process, the edges of the parts to be joined are heated to melt. They are joined when cooling is done. Filler materials and pressure can be applied but not compulsory. It totally depends upon the specific process and part needs.

More evolved version of this are Gas Welding, Laser Beam Welding, Electron Beam Welding etc.

3. Pressure Welding OR Forge Welding:

Unlike Fusion Welding, heat is not necessary in Pressure/Forge Welding. It may or may not be there. Here, joining of metals is done by applying pressure. Blacksmith can be good example for this type. Metal joining can be achieved by hammering metal parts.

4. Soldering, Brazing:

This welding process is mostly the weakest kind of join within above described. In this welding, parts to be joined are not brought to molten state. Instead, filler material is melted in and applied at join. Usually, filler material has low melting point. It is melted using torch. It is popular joining process for electronics related things. This process can be very well automated.

These are main types of welding. These types, depending on work needs, are developed and evolved into much finer welding processes like TIG welding, MIG Welding, Underwater Welding and many more.

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1. Notes on Gas Welding

Recently, I had chance to help one of my friend in hiring the people for his small software company. Positions were mainly for web based application developers. I interviewed about 15 people and handed over the shortlist to him. That was my first and important experience to be an interviewer. Now, me too, thinking of hiring some people on payroll. So, I started reading some material over the web about the topic Employing People and related stuff. Listed below are some good points, I would like to share with my readers. Hope, its useful for you!

Image: renjith krishnan / FreeDigitalPhotos.net

Interview Preparation Tips – Interviewer Point of View:

1.  For every small company, started by one or few individuals, there comes one point where they can hire more people.
2. Adding employees does not always mean adding more costs to your business in form of employee benefits, bookkeeping, salaries etc. If planned properly, employees can add good value to your company.
3. You can not do every task by yourself. Sometimes, delegating the task is best way to get the works done.
4. Getting tasks done by others brings you with great benefit of time. This can let you focus on your area of expertise e.g. creating new product ideas, creating sales plan or anything in your field.
5. More people working at your firm means increased number of customer you can supply to. With limited number of people it is really hard to deliver product/service to large set of customers.
6. Higher unemployment in market means better chances of getting the good employees at lower cost than normal times. Also, freshers from the colleges could be good employees if chosen and trained properly.
7. Another personal benefit is to you. You get a team to manage and lead. So, you get to work on your managerial and leadership skills which are timeless.
8. Similar to preparing for interview as a candidate, you must do your homework while preparing for being interviewer.
9. Prepare a set of questions and make sure to ask open ended questions. Open ended means the question that needs some explanation. Make the candidate speak for most of time.
10. If you are asking technical questions, offer pen and paper.
11. Once, with my friends, we had worked on a documentary. There I learn this thing. We had so many video clips and had to select from from them on various criterion like video quality, camera shakes, content importance and relevance etc. So, instead of deciding one by one we played all of them in a row. We, all team members, started taking down the things on paper. In the end, we compared our opinions from paper. All the good scenes were captured very easily and effectively. So, while you interview the candidate don’t forget to take down your opinions on paper.

So, this is all in my list of preparation for being interviewer and I am still studying.

Do you wanna add up something to it? Please use comments section below!

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Video Conferences:

Video Conference is meeting of people over video and audio bridge. These people can be from two different locations or more than two locations. Video conference is one of very important gift of Technology.With evolution in fields of Electronics and Networking, video conferences have becoming more functional and more easy on basis of cost.

Needs of Video Conferencing:

• These days, businesses and works are becoming more and more global. Various units of company reside at different places in world.
• Client and Service Provider are in different countries.
• Interview candidate is lot away from company location.
• Students and Teachers can not come at one place due to geographic distances, costs and political boundaries.
• Families are away and you need the face to face communication.

Major Uses of Video Conferences:

There are many places when only audio communication can not play the whole part properly. Eye to eye contact is really necessary. In these cases Video Conferencing can solve the purpose very effectively and very low cost than actual journey.

Audio Phone Communication really becomes deficient when participants are either deaf or have hearing problems or mute. These people communicate through sign language. Video Conferencing can solve the purpose and communication can be carried out as good as face to face.

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Mahindra XUV500

Indian Automobile Company Mahindra, brings up a blast with XUV500, their new SUV. The XUV500 is launched in W6, W8 and W8 AWD versions. Its Ex-showroom cost at Delhi starts from 10.8 Lakh and top model which is XUV500 W8 AWD, Ex-Showroom cost is about 13.4 Lakh.

Specifications and Price Details of Mahindra XUV500:

• Power (PS@rpm) :  140@3750
• Torque (Nm@rpm): 330@1600
• Fuel: Diesel.
• Gear: 6 Speed Manual.
• Engine Type: mHawk140 Engine with VGT Technology.
• Seating Capacity: 7.
• Fuel Efficiency(Average/Mileage): 15 KMPL.
• XUV500 W6 Price: 10.8 Lakh (Ex-Showroom Delhi).
• Booking Opens: Today(1st October, 2011).

Check out official site and Download Mahindra XUV500 Wallpapers here.

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Safe Moneymaking Paradigm From Years:

From years, we can see people going to jobs they don’t like. Many of them, every morning reach to office/factory/work place, spend 9/10/12/14 hours there on some task, like writing something into papers/working on same machine/ similar things. And this is picture for 20-25 even more years of their lives.

These people spend almost half of their lives, during very productive age, at the place which they don’t deserve/want to be. And most of time they are underpaid or paid just enough to afford OKAY lifestyle and LIFE.

Trading Your Time & Active Income:

Moneymaking is, most of times and for most of people, trading for time. For example, a worker trades his 8 hours for daily wages or call center people are paid on per hour basis or software professionals are supposed to work at least for 40 hours in office to get paid.

I am not saying that getting paid by time trading is bad idea, but your income stops as soon as you stop trading the time. That is why this kind of income is called as Active Income. You get paid as long as you are Active at your workplace.

Passive Income:

When you ask yourself  question, how to make more money, you better focus on generating some Passive Income assets. These will be the assets bringing in money for you, even when you are asleep.

Passive Income sources are somewhat automated income sources which brings in money for you without eating up a lot of your time. These passive income sources ask for onetime Time investment or small size chunk time investments.

Unlike Onetime Time Investment, chuck time investment sources need little more to design an automated system! Automation is mechanical engineering term in which a system can work completely by itself without human intervention. What it needs is simply, some maintenance and supervision to check if everything is going well n fine. Properly planned and executed passive income sources can reach to automation mode.

Passive income gives you some security. If eventually, it becomes too large then you can quit your day job and focus on your personal skills, refine them. Due to refined skills you can charge more on per hour basis and this can improve your Active Income too. Job satisfaction, monetary sound feeling, sense of abundance are added benefits!

Check out Related Books on Amazon:

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Introduction:

Success is Process, not the destination. Everybody emphasizes this, don’t they! Similar is the case with Learning. It also is ongoing process with full of challenges and excitements. Biggest reason or obstacle  in Growing/Learning Fear. Fear is the reason, that makes us procrastinate the things and eventually things disappear.

Tim Ferriss:

Tim Ferriss is Bestseller Author and Public Speaker. He is known for his Analytical Approach to kill the fear and learn the new skills. What Tim actually does is, uses analytical approach to understand fully, his fear/problem/challenge. And when he understands it, its not that scary!

It is like mathematics. It is totally absurd when we don’t understand the rules. And as soon as we take time and understand the rules, everything makes sense.

Tim Ferriss have been at TED, one of most renowned stages in the world. He explains his analytical approach on the stage with his real life examples which include Swimming Fear, Learning New Language (Japanese!!) etc.

The 4-Hour Work Week:

The 4 Hour Work Week is Tim’s best selling book. Tim Ferriss has coined some renowned concepts like “Lifestyle Design” and “Mini Retirement”.

Tim has simple four step Self Improvement program:

• Define Aspirations.
• Managing Your Time.
• Creating Automatic Income – Passive Income.
• Escaping 9-5 Boring Life.

Check Out The Books From Tim Ferriss:

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Information Technology (IT) is huge industry emerged in last few years. These are the places where huge number of people are working in and making huge monetary transactions. In this article, we will see some of the job profiles that Software Development professional are working in. Here are the career opportunities in IT/software industry.

6 Job Profiles In Any IT/Software Industry:

1. Project Management:

Key person here, is Project Manager. He is the leader of the team. Success/Failure of project becomes his responsibility. Most of times project manager leads more than one project. It also depends on the size of teams and project. He needs to keep up with clients, requirements, timelines, obstacles and financial things too.

2. Solution Architect:

Solution Architect understands the systems and suggests the solutions. Solution Architect needs to understand actual business to work effectively. Also, she must be aware of Software/IT developments. This work is on join of Actual Business and Software Development for the business.

3. Software Developer/Web Developer:

This is actual person who writes the code. And this is the person whose time goes through payroll time clocks and every hour is charged to customer. Also, support industry comes in similar category. Software/Web developer must be expert in Logic and programming with respective languages.

4. Database Administrator:

This person manages the databases. Uses of database can vary. It can be for supporting some supportive system or for software itself. In short this is the person who rules the database. He must be master.

5. Service and Support:

Software development needs infrastructure and environments. Service and Support teams are on fire if development cycle is interrupted due to some system failure.

6. Network Administration and Security:

Software development in large teams, remote locations, multiple systems, multiple types of systems demands high quality network administration. Security is another important aspect of networks when it comes to things like crucial data of companies, business logic, banking like things.

payroll time clocks

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