Further manufacturing walk through
Second electron gun for SEM postiioned close to the sample with mechanical XY positioning
Given Electricity is 2kwh per hour .5Euro/hr
Previous examples ignoring ion beam correction gave manufacturing times of Part A 2480 min 1.7 days part B 248 min 4 hrs
with seperate second SEM electron Gun with XY mechanical movement
at max speed of movement of 0.3m per second then manufacturing part A 2866 min 2.0 days B 287 min 4.8 hrs
So 15 percent longer manufacturing time as well as 2 extra motors ( one vacuum tolerant / expensive ) and extra position sensors and extra computer processing putting the patches together as one image. But advantage of normal sized PIN diode sensors for SEM in backscatter mode as sensors only 0.1m from sample like a traditional SEM rather than 1m distance from sample a new situation ( see below for detailed caculation).
Part A Stainless size 300x300x200mm 15Kg
10µ Stainless powder (40Euro/kg) melt print 100µ Z layer thickness
1 minute per Z 100µ each layer heated melting-point – 20 0C then printed by beam
5.33 minute per Every 10th layer Z axis correction see below ;
SEM ( part assumed to occupy 1/9 of whole print area; 1/9* 300*300=10 000mm2 measurement at every 10µ, SEM picture 500x500 pixel so 5mmx5mm, So for 10,000mm2 need 400 SEM pictures 10,000/25= 400 4x pictures from 4 picups gives effect of different angles? for 3D picture reconstruction so real distances, 400 5mmx5mm pictures, 250ms a picture = 100sec. plus time of mechanical movement of electron gun between .024m square patches at .03m per second is 12y strips each 0.3m strip takes 10 seconds to travel, so in all takes 120 seconds to cover build area( Risk of underestimate factor x100 ) 100+120=220 or 3.66 min
Remove metal by Vaporization 1ms per 70µ diameter spot area 4000x10-6 mm2 ( 850µs duration & 150µs beam movement) 1/10 of part high(Risk of underestimate factor x2) ( 1/10*10 000mm2/ 4000x10-6 mm2= 1x105 spots 1x105 spots*1ms= 100Sec 1.66min
Time so far 200* Z correction layers 5.33 Min each 1066 + 1800 printed layer 1min each = 2866 min ( 2.0 days)
Cost 690 Euro materials 600Euro Electricity 90
Part B Aluminum size 300x300x20mm 1.5Kg
Aluminum 15Euro 10µ powder, melt print 100µ Z layer thickness
Time 20* Z correction layers 5.33 Min each + 180 printed layer 1min each = 287 Min 4.8 hours
No ion beam abraison
Cost 27 Euro materials 22 Euro Electricity 5 Euro
