Welcome to the Glossary! If you are facing any difficulty understanding the terms below please feel free to ask for support in the forums! For a more detailed explanation of the terms used in the Metalbot project please take a look at the terminology page.
- Additive Manufacture (AM)
This refers to any process which adds material in order to fabricate an object. The more widely used 'reverse' of this process is called "subtractive manufacture", more commonly known as machining or milling. The benefits of additive over subtractive manufacture is that there is very little material waste! Perhaps the biggest plus that additive manufacture has to offer is the ability to create any internal geometry. This is impossible for traditional methods. Additive manufacturing machines ranges from small and inexpensive desktop 3D Printers that cost only $200 all the way through to high end laser sintering machines in excess of $1,000,000.
- Electron Beam Melting (EBM)
Electron beam melting is identical to the SLS process except for two critical parts. First, instead of sintering the powder with a laser a high power 'electron beam' is used. The electron beam is generated in a similar way to the electron beam inside old Cathode ray tube TVs, but on a grander scale. The second difference is the use of a vacuum chamber critical for the electron beam to travel in.
Fused Deposition Modeling is the the main process used on hobbyist plastic 3D printers such as the RepRap. The plastic is in the form of a filament that is coiled up. This filament is pushed into an extruder which heats the plastic until it melts, much like a glue-gun. The extruder head is connected to a gantry which plots out the cross section of the object being printed.
- Laser Scanner
Laser scanners are clever devices! They consist of two mirrors attached to special motors called Galvanometers. A laser beam is then shot at one of the mirrors, reflected to the second and finally down onto the powder below. According to the combined angle of the two mirrors, any x-y cross section below the scanner can be melted by the beam. With a system like this, laser beams can melt large areas relatively quickly.
- Laser Wattage
The wattage of a laser along with it's wavelength determines the power of the laser. A typical laser engraver, with a wavelength of approximately 1000nm, will have a laser wattage of 10-50 watts of beam power. Laser power is measured in watts - the same watts used to measure the power of light bulbs. A 10 watt laser will appear much brighter than a 10 watt light bulb since the light from the bulb travels in all directions and spreads rapidly, while the light from the laser is concentrated in a beam only a few microns in diameter.
- Metal Printer
A 'Metal Printer' simply refers to any machine that can take 3D CAD data and convert it into a real life 3D object made out of metal.
A micron is a unit of measurement based on the metric system. A 'micron' can also be called a 'micrometer' and is typically abbreviated 'um'. It is an SI unit of length equaling 1×10−6 of a meter. That is about seven times smaller than a red blood cell! Because precision is very important when we are dealing with 3D Metal Printing we typically measure things in microns. It is not uncommon to deal with metal powders that have a granule size of less than 5 microns! The micron is a very important unit of measurement.
A Nanometer is the next order of magnitude smaller than a micron, 1000nm equals 1um. A nanometer is simply a unit of measurement based on the metric system. The nanometer is often abbreviated to 'nm', and is equal to one billionth of a meter. The nanometer is a convenient unit for measuring the length of light waves. For example the wavelength of a Nd:Yag laser is about 1060 nanometers. This length is considered 'infrared light' while visible light ranges from 400nm to 800mn. The diameter of a helium atom is about 0.1 nm, so the nanometer is a truly small length!
- Powder System
This refers the machinery inside a printer that handles the powders. In terms of the SLS process this can be thought of as three subsystems that work together. 1 - The powder dispenser, 2 - The powder roller which spreads the fine layers, 3 - The powder recycling which collects all the excess powder.
- Selective laser Sintering (SLS)
This is one of the main processes that we are looking at here at Metalbot. Please take a look at 'How does it work?' at the top of this page.
To sintering something means to melt powders. Sintering depends on atomic diffusion. This means that when a powder is heated up close to it's melting point, the atoms that form the powder granules start to diffuse into the adjacent powder granule fusing the granules together. When very high temperatures are used, the powder will completely melt together leaving a very high density (and no pores, pores are bad).
TI-AL6-V4 is the most commonly used alloy of Titanium. It is composed of titanium (90%), Aluminum (6%) and Vanadium (4%). This alloy is extensively used in the aerospace industry for it's high strength and is substantially stronger than pure titanium. This is one of the main materials that we want to work with the Metalbot.