SLAG -WELDING

                             Slag (welding)

Examples of arc weld slag

Welding slag is a form of slag, or vitreous material produced as a byproduct of some arc welding processes, most specifically shielded metal arc welding (also known as stick welding), submerged arc welding, and flux-cored arc welding. Slag is formed when flux, the solid shielding material used in the welding process, melts in or on top of the weld zone. Slag is the solidified remaining flux after the weld area cools.

Flux

Shielded metal arc welding process, showing slag

Welding flux is a combination of carbonate and silicate materials used in welding processes to shield the weld from atmospheric gases. When the heat of the weld zone reaches the flux, the flux melts and outgasses. The gases produced push the atmospheric gas back, preventing oxidation (and reactions with nitrogen).

The melted flux covers the molten metal in the weld zone. Flux materials are chosen so that the density of the melted flux / slag is lower than that of the metal being welded, so that the flux floats to the top of the weld puddle and leaves pure or nearly pure metal to solidify below.

Flux materials may also contribute to metal behavior in the molten metal, with physical or chemical alterations to the molten metal.

The flux cover also helps thermally insulate the weld and reduce the cooling rate.

Flux-core arc welding process, showing slag

Inclusions

Submerged arc welding process, showing slag

It is possible for areas of slag to become embedded within the solidified metal, if it did not float to the top of the molten metal for some reason. These are called inclusions and are a form of welding defect. Inclusions may be visible on the surface after cleaning, or may be completely contained within the metal, in that case they can only be detected on X-rays of the weld, requiring grinding or drilling to remove (followed by re-welding that section).

Processes

Electroslag welding process, showing slag

Four welding processes use flux in slag-producing manners:

Shielded metal arc welding, also known as SMAW

Flux-core arc welding, also known as FCAW or FC

Submerged arc welding

Electroslag welding

Removal of slag

Slag does not contribute to strength or protection of metals after the welding process; it is waste material. Removal of the slag is necessary for four reasons:

ability to inspect the quality of the weld area;

aesthetics, or visual appearance;

if a second layer or pass of welding is to be made on top of the first;

to clean and clear the surface for coatings such as paint or oil.

Removal is usually done using manual or power tools. Manual tools may include a welding or chipping hammer, which has a pointed tip on one end to break up large chunks of slag efficiently, or wire brushes. Power tools include angle grinders with grinder disks or wire brush wheels.

TRANSPARENT CONCRETE

                                      TRANSPARENT CONCRETE

Transparent concrete or light transmitting or translucent concrete is a concrete which transmitting light through it by using optical fibre. It is material which makes green building. Conventional concrete made with the mixture of cement sand aggregate and water which is unable to transmit lights, transparent concrete is made with cement, very fine sand and thousands of optical fibre reinforced in concrete from one face to another face which guide the light passing through it. Due to development of glass and optical fibre works on transparent concrete will increases. Transparent concrete is not different from conventional concrete it has same material with addition of optical fibre. In many concrete fibres are used to increase the tensile properties of concrete but in transparent concrete optical fibres are not used for such purpose it transmits only lights.

MATERIAL FOR TRANSPARENT CONCRETE

1. Cement – Transparent Concrete is generally used for transmit light therefore no special cement is requires for it. Ordinary Portland cement of 43 grade can be used.

2. Sand - Sand passing through 1.18mm size sieve should be used.

3. Water - Water is used for mix all ingredient of concrete. For making transparent concrete portable water should be used.

 4. Optical fibres - An optical fibre or optical fibres is a flexible, transparent fibre made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibres are used most often as a means to transmit light between the two ends of the fibre and find wide usage in fibre-optic communications, where they permit transmission over longer distances and at higher bandwidths (data rates) than wire cables.

WORKING PRINCIPLE

Transparent Concrete is based on “Nano-Optics”, fibres are act as slit and carry light throughout. Thousands of optical fibre is reinforced from one face to another and transmit lights. When light traveling in an optically dense medium hits a boundary at a steep angle (larger than the critical angle for the boundary), the light is completely reflected. This is called total internal reflection. The process of total internal reflection is shown below. This effect is used in optical fibres to confine light in the core. Light travels through the fibre core, bouncing back and forth off the boundary between the core and cladding. Because the light must strike the boundary with an angle greater than the critical angle, only light that enters the fibre within a certain range of angles can travel down the fibre without leaking out. This range of angles is called the acceptance cone of the fibre. The size of this acceptance cone is a function of the refractive index difference between the fibres core and cladding.

 ADVANTAGES OF TRANSPARENT CONCRETE

1. According to principle of building planning the building must have good aesthetical view. Transparent concrete makes it possible.

2. Where two building is very near to each other there are no lights inside the building, transparent concrete is beneficial for that place.

 3. It emitted less amount of carbon.

 4. It is Energy Saving.

5. It provides facility to see an image of person stands on outside of the door.

DISADVANTAGES OF TRANSPARENT CONCRETE –

 1. The main Disadvantages of this concrete is excessive cost due to use of optical fibre.

2. It requires skilled labour for installation of optical fibres.

COMPARISON BETWEEN CONVENTIONAL AND TRANSPARENT CONCRETE –

1. Transparent concrete is costly as compare to conventional concrete.

2. Good aesthetical appearance than conventional concrete.

3. Strength is almost similar to conventional concrete.

APPLICATION

The transparent concrete is a good architectural material. As discussed in various papers the strength of concrete is reduced by some amount but it can be achieved by using some addition fibre, therefore the strength parameter of transparent concrete is same as conventional concrete. Transparent concrete gives aesthetical view to buildings. It is energy efficient and makes green building.

GREAT RENDERS FROM LUMION PART 1

     GREAT RENDERS FROM LUMION

Lumion is intuitive and the functionality is easy to apply but what do you want to communicate artistically and how do you achieve that in Lumion? 

Building an artistically compelling still image or animation in Lumion requires a vision of what you want to achieve: What emotions do you want to convey? Are you going for light & colorful, grey & bleak or something else? Should the images look realistic or sketchy? Which parts of the building are you trying to emphasize?

Here are 5 tips, including extra hints, from Alexander of the Lumion team. He plays a leading artistic role in creating Lumion promo videos as well as in programming Lumion. It’s fair to say he has a special flair for making compelling images and animations.

1. Find the best point (or points) of view in your scene

·         Still shots should be balanced by at least one composition rule. There are many rules you can use but the more the better.

·         The camera height should for much of the time during an animation, be set at human eye level. The camera angle shouldn’t be too wide so as to avoid perspective distortion.

2. Set up the lighting

·         Find the best position for the sun to attract maximum attention to the parts of the building that you want to highlight. Use the sun study effect, if you want to accurately simulate the sun location at a particular location, time and date. 

·         Add Interior and mood lighting, even if it is a day shot, this communicates in a subtle way that the building is being used. You can also use volumetric lighting for extra atmosphere.

·         Balance the shadow brightness and coloring depending on situation, in outdoor shadows always a bit more blue.

·         Avoid high contrast in non-important areas otherwise these high contrast areas can sometimes direct attention to the wrong points in your design.

3. Make your materials look good

·         Always enable SpeedRay reflections and put reflection planes on big flat surfaces.

·         Glossiness of the floor and ceiling always should be tweaked after applying materials, more often extra reflectivity is better than less reflectivity.

·         Do not use simple digital colors, like plain green, red, blue, purple, yellow. It looks ugly and it’s always better to find natural, more realistic, “flat” colors.

·         Sometimes it is better to replace diffuse texture with plain color (using top slider in material editor) and also use bumps but without maximal intensity.

4. Adding effects

·         Use color correction, especially the first slider, as it adds dark shadows where necessary.

·         Add a little bit of chromatic aberration and a very tiny value of fish-eye for a small optical imperfection.

·         Add Hyperlight for still images. When doing this use an intensity higher than 100%.

·         To make the picture a bit ‘flat’ like print on paper, use the sharpness effect and put the slider on minimum, sometimes it helps.

·         Depth-of-Field (DOF) is really useful for narrow camera angles, but better to not use it with the wide ones.

·         Always put reflection on water.

5.Extra details - every single shot needs it!

·         Furniture, for interiors and exteriors is very important. Select and add objects from the Lumion object library. Place some in empty spaces.

·         Cars are good for border areas of a picture. Try to avoid having cars in the center of the composition.

·         People are important but try to place them such that they do not dominate the picture. Their faces should not be too visible. Using silhouettes from the library is a good way to achieve neutrality.

·         Trees and plants are very good for picture borders and background.

·         The background is super important, even if it’s blurred, the feeling of a real city or forest adds a lot to the feeling of a real building. For example birds can be a nice detail to make the sky look more natural.

·         Try using blurred clouds (softness slider), or disable cloud completely, clear sky is very good if you need extra attention on the building itself.

                                              

Most Popular Types of Flooring Materials for Your House Part 1

Most Popular Types of Flooring Materials

 for Your House Part 1

Furniture and fittings, you may be able to change with the time however the flooring is something there for a very long period of time. As choosing your flooring needs lots of effort and also it will cost you a fortune. Also, choosing new flooring for your new home is not an easy task. There are so many options available for flooring materials to choose from a wide range from the market. There are various types of flooring materials are available in the market, so it is bound to happen where people get confused while choosing which flooring material is best for their home.

Choosing flooring materials usually depend upon the following criteria:

·         Uses

·         Quality

·         Traffic (High, Low or Medium)

·         Difficulty of Installation

·         Required Level of Finishing

·         Maintenance i.e. Cleaning

·         Economy

Types of Flooring Materials

01. Tiles Flooring

Amongst all the type of flooring used in the house, “tile flooring” is a very common and popular. The tiles are available in varieties of colours, textures and patterns.

Tiles flooring also have types like vitrified tiles, ceramic tiles, porcelain tiles, etc. We have tried to give a brief explanation on all various types of tiles:

01(a) Ceramic Tiles Flooring

Ceramic tile is made up of mixture of clay and water only. It is used in indoor as well as outdoor areas. Ceramic tiles are ideal for wet areas like bathrooms, kitchens, etc. as these tiles are not very slippery as compared to vitrified tiles.

01(a) Vitrified Tiles Flooring

Vitrified tile is one type of ceramic tile with low porosity. Vitrified tiles are most commonly used in living room, kitchen, bedroom, etc. They have a glossy finish as compared to ceramic tiles though they are also available in Matt finish.

There are various types of vitrified tiles available in the market like;

·         Full Body Vitrified Tiles:

Full body vitrified tiles have pigment in entire thickness of the tile. Therefore, scratches are less noticeable in these types of vitrified tiles. Also, when you have to cut the tiles, borders of tiles will be of the same colour.

·         Double Charge Vitrified Tiles:

Double charge vitrified tiles are fed through a press that prints the pattern with a double layer of pigment (two kinds of colours are fed into the machine). Therefore, the upper layer becomes 3 to 4 mm thicker. So, it is a viable option where traffic is medium to heavy.

·         Soluble Salt Vitrified Tiles:

Vitrified tiles are printed with screen printing technology and then polished, therefore it is called soluble salt.

·         Glazed Vitrified Tiles:

Glazed Vitrified Tiles (GVT) has a glazed surface. This glazed surface allows any type of design, surface textures, etc. on it. It can increase the aesthetics of the area.

01 (c) Porcelain Tiles Flooring

Porcelain tiles are the type of vitrified tiles. It is not majorly used nowadays. Porcelain tiles can be used in living room, bedroom, etc. It is staining and water resistant.

02. Stone Flooring

Stone flooring is natural, beautiful, and always stylish that stands out in contrast to any synthetic or manufactured stone products. Natural stone also comes in different types such as granite, marble, limestone, slate, travertine, sandstone, etc. All the types of stone have different characteristics. The naturally cool, hard surface is ideal for warm climates.

02(a) Marble Flooring

Marble is a metamorphic rock. When properly finished it can transform the area beautifully.  Marble flooring is very common in residential and commercial buildings, temple, hotels, hospitals etc. The most popular marble available in India are Makarana Marble, Italian Marble, Ambaji Green Marble, Kesarayaji Green Marble, etc. It is a better flooring option than granite flooring as it is cheaper.

02(b) Granite Flooring

Granite is igneous rock. Granite flooring a is a type of natural stone flooring and it is most suitable for the kitchen area. It is also used in an outdoor area like pathways. Granite flooring does not feel as cold as marble does.

02(c) Limestone Flooring

The limestone has beautiful textures as they are sedimentary rocks by nature. Limestone flooring is perfect choice for bathrooms, dining rooms and hallways. Limestone flooring does not have that pattern as compared sandstone flooring.

 

02(d) Sandstone Flooring

Sandstone flooring is composed of loose grains of quartz sand that are rough in texture. The natural beauty makes sandstone flooring great for interior floors as well as exterior decoration including flooring, paving, parking, etc.

02(e) Slate Flooring

Slate flooring is a made up of metamorphic rock that was formed in layers, so it easily splits into thin sheets that are cut into tiles. Rougher surfaces of slate flooring are perfect for entryways, patios and kitchens.

02(f) Kota Stone Flooring

Kota Stone is a type of stone flooring. It is cheaper than marble flooring.  It can be used in lobby, balcony, pathways, etc. It is not attractive as compared to marble and granite flooring. Cleaning of kota stone flooring is difficult.

02(g) Travertine Flooring

Nowadays, the travertine is one of the softest floorings available in the market. It is most commonly used in kitchens and bathrooms. Travertine flooring can be more susceptible to staining than granite or marbles.

03. Wood Flooring

Wood flooring is very old type of flooring material; however, it has never been outdated. It is used under special circumstances such as in hilly areas and in damp places. With proper care and maintenance, wood flooring can last a long time. There are various types of wooden flooring which are commonly used:

03(a) Solid Wood Flooring

Solid wood flooring is made from a piece of wood which has thickness of around 20 mm. Solid wood flooring can be installed in any room of your house, except in areas where there is high moisture content such as kitchen, bathrooms and basements.

03(b) Engineered Wood Flooring

Engineered wood flooring is made with the core of plywood and a layer of solid wood attached on its top. It can be installed even in kitchen areas, apart from other rooms of your house. Engineered wood flooring gives more attractive look than laminate wood flooring.

03(c) Laminate Wood Flooring

Laminate wood flooring is obtained by placing a layer of a photographic image of wood over a fibreboard. As it is a synthetic product, it does not give look and feel of natural wood. Laminate wood flooring can be installed in any room such as living room, bedroom, and dining room except wet areas like bathroom and laundry rooms.

to be continue in next blog...............