Scan spacing is the separation between two consecutive laser beams. It is also called hatch spacing or hatch distance (15). As shown in Figure 11, it is measured by a distance from the center of one beam to the center of the next beam.
What is Hatch in 3D printing?
The line-based halftoning principle called ‘hatching’ is applied to the line pat- terns naturally occuring in FDM prints, which are built up in a layer-by-layer fashion.
What is PBF in additive manufacturing?
Powder bed fusion (PBF) is an additive manufacturing process and works on the same basic principle in that parts are formed through adding material rather than subtracting it through conventional forming operations such as milling.
What is keyhole in additive manufacturing?
In keyhole-mode laser welding, the power density of the laser beam is sufficient to cause evaporation of the metal and formation of plasma. Metal evaporation causes the development of a vapor cavity that enhances the laser absorption.
What is scanning speed in additive manufacturing?
Application cases of additive manufacturing materials
The processing parameters are as follows: laser-scanning speed is 1700 mm/s, laser-scanning pitch is 0.10 mm, laser power is 12 W, laser energy density is 73.5 mJ/mm2, and the preheating temperature is 100°C.
What is Hatch space?
Scan spacing is the separation between two consecutive laser beams. It is also called hatch spacing or hatch distance (15). As shown in Figure 11, it is measured by a distance from the center of one beam to the center of the next beam. Scan spacing is directly proportional to the production speed.
Why is powder bed fusion used?
Powder bed fusion of polymers
Powder bed fusion (PBF) is a subset of additive manufacturing (AM) whereby a heat source (eg, laser, thermal print head) is used to consolidate material in powder form to form three-dimensional (3D) objects.
Who uses powder bed fusion?
The medical industry is a major adopter of 3D printing technology – especially powder bed fusion. This is in part due to the wide range of biocompatible materials that are well-suited to these printers as well as the fact that the process can produce a variety of complex geometries.
What is laser additive manufacturing?
Laser-based additive manufacturing (LBAM) is a family of advanced production systems, use to fabricate metal parts, complete functional and functionally graded products (Li et al., 2017; Loh et al., 2018; Ocelík and De Hosson, 2018), see Figure 1.
What is the fundamental issue that causes porosity in PBF?
Voids or internal porosities in L-PBF might occur under two completely different conditions of insufficient [8,11] and excessive heat input . More specifically, the former condition leads to lack-of-fusion voids while the latter leads to keyhole-induced pores.
What is keyhole porosity?
Keyhole pores are formed when the vapor bubbles are trapped within the melt pool, which occurs at higher energy densities, and lack of fusion pores are formed when some regions remain unmelted as a result of lower energy density.
What is Keyholing in 3d printing?
The research shows that keyholes form when a certain laser power density is reached that is sufficient to boil the metal. This, in turn, reveals the critical importance of the laser focus in the additive manufacturing process, an element that has received scant attention so far, according to the research team.
What is scan speed in SLM?
The detailed characterizations for the parts produced by the SLM process are evaluated. An SLM scanning speed of 695, 775, or 853 mm/s was selected. The findings show that a high quality of surface morphology and microstructure is obtained at a scanning speed of 775 mm/s.
How do you calculate scan speed?
Acquisition speed is calculated by multiplying two values: frequency (number of laser lines recorded per second) and the number of points on each laser line. Thus, a scanner with 1000 points per line with a frequency of 150Hz delivers an acquisition speed of 150.000 points per second.
What is scan speed?
Scan speed is specified as 200, 400, 800 and 1000 Hz in Sp2 confocal microscope. It refers to the frequency of two galvanometers which drive scanning mirror shading laser light across specimen. In practical, the value tells how many lines per second are scanned on the specimen.
Tutorial Magics: How to Generate Supports for Metal Printing
Fusion 360 — How To Use The Pattern Function
3D Printing: Hatch Distance and Scan Distance