(19)
(11)EP 3 685 939 A1

(12)EUROPEAN PATENT APPLICATION

(43)Date of publication:
29.07.2020 Bulletin 2020/31

(21)Application number: 19210022.0

(22)Date of filing:  19.11.2019
(51)International Patent Classification (IPC): 
B22F 3/00(2006.01)
B29C 64/153(2017.01)
B29C 64/214(2017.01)
B33Y 40/00(2020.01)
B22F 3/105(2006.01)
B29C 64/205(2017.01)
B33Y 30/00(2015.01)
(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA ME
Designated Validation States:
KH MA MD TN

(30)Priority: 25.01.2019 US 201916258121

(71)Applicant: Hamilton Sundstrand Corporation
Charlotte, NC 28217-4578 (US)

(72)Inventors:
  • BINEK, Lawrence
    Glastonbury, CT Connecticut 06033 (US)
  • MORGANSON, David W.
    East Hartford, CT Connecticut 06118 (US)

(74)Representative: Dehns 
St. Bride's House 10 Salisbury Square
London EC4Y 8JD
London EC4Y 8JD (GB)

  


(54)ENHANCED RECOATER EDGES


(57) An additive manufacturing device includes a build platform (102). A recoater (108) is operatively connected to the build platform (102) to move relative to the build platform (102) to coat unfused powder onto a build on the build platform (102). The recoater (108) includes a recoater mount (110) defining a length-wise receptacle (112) therein, and a recoater blade (114) seated in the receptacle (112). A blade reel system (116) is operatively connected to the recoater (108) to replace the recoater blade (114) in the receptacle (112) during a build on the build platform (104).




Description

BACKGROUND


1. Technological Field



[0001] The present disclosure relates to additive manufacturing, and more particularly to controlling geometries in additive manufacturing techniques such as laser powder bed fusion, and the like.

2. Description of Related Art



[0002] Laser powder bed fusion additive manufacturing and electron beam additive manufacturing use directed energy in conjunction with powder feedstock to form a sintered structure. The energy source, e.g., the laser beam or electron beam, excites the target material to the point of phase-change. This melt-pool process, coupled with an active toolpath effectively welds a single layer of powder feedstock into a solid state. Once one layer has been formed, a recoater pushes a thin layer of powder feedstock across the build surface and the process repeats.

[0003] Build quality is often dependent on the state of the recoater blade, which is a wear part that has to be replaced relatively often. Some powder metals are more abrasive than others. As a recoater blade degrades due to friction, the recoating quality may begin to fail. This may be exhibited by clumps of material being dropped by the recoater back onto the build surface. These issues can cause build failures.

[0004] The conventional techniques have been considered satisfactory for their intended purpose. However, there is an ever present need for improved additive manufacturing systems and methods. This disclosure provides a solution for this need.

SUMMARY OF THE INVENTION



[0005] An additive manufacturing device includes a build platform. A recoater is operatively connected to the build platform to move relative to the build platform to coat unfused powder onto a build on the build platform. The recoater includes a recoater mount defining a length-wise receptacle therein, and a recoater blade seated in the receptacle. A blade reel system is operatively connected to the recoater to replace the recoater blade in the receptacle during a build on the build platform.

[0006] The blade reel system can be mounted stationary relative to the build platform outside of a build area. The blade reel system can include a reel configured to feed fresh recoater blade material into the receptacle, replacing used recoater blade material. The blade reel system can include a cutter operatively connected to cut fresh blade material to free the recoater from the blade reel system to recoat the build area using the fresh blade material.

[0007] The blade reel system can be mounted to the recoater for movement together with the recoater relative to the build platform. The blade reel system can include a supply reel and a take up reel on opposite ends of the recoater mount. The supply reel and take up reel can be configured to reel blade material through the receptacle as the recoater passes over the build area. The supply reel and the take up reel can be configured to reel the blade material back and forth as the recoater passes over the build area.

[0008] The blade reel system can include a magazine with adequate capacity to hold a reel of recoater blade material sufficient to completely replace the recoater blade material with each pass of the recoater over the build area during a build.

[0009] A method of additive manufacturing includes recoating powder over a build area using a recoater and selectively fusing a portion of the powder to a build in the build area. The method includes replacing a recoater blade in the recoater with the build in progress, and repeating recoating, selectively fusing, and replacing the recoater blade until the build is complete.

[0010] Replacing a recoater blade can include moving the recoater beyond the build area to a blade reel system. Replacing the recoater blade can include reeling fresh recoater blade material into a receptacle of the recoater. The method can include cutting the fresh blade material to free the recoater to recoat the build area using the fresh blade material.

[0011] Replacing a recoater blade in the recoater can include moving a blade reel system together with the recoater and reeling blade material through the receptacle as the recoater passes over the build area. Reeling blade material through the receptacle as the recoater passes over the build area can include reeling the blade material back and forth in the recoater receptacle as the recoater passes over the build area.

[0012] Replacing the recoater blade can include completely replacing the recoater blade for each recoating pass of the recoater over the build area.

[0013] These and other features of the systems and methods of the subject disclosure will become more readily apparent to those skilled in the art from the following detailed description of the preferred embodiments taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS



[0014] So that those skilled in the art to which the subject disclosure appertains will readily understand how to make and use the devices and methods of the subject disclosure without undue experimentation, preferred embodiments thereof will be described in detail herein below with reference to certain figures, wherein:

Fig. 1 is a schematic plan view of an exemplary embodiment of an additive manufacturing device constructed in accordance with the present disclosure, showing a blade reel system that is stationary relative to the build platform;

Fig. 2 is a schematic perspective view of a portion the device of Fig. 1, showing the recoater blade material seated in the receptacle of the recoater mount; and

Fig. 3 is a schematic plan view of another exemplary embodiment of an additive manufacturing device constructed in accordance with the present disclosure, showing a blade reel system that is mounted for movement together with the recoater relative to the build platform.


DETAILED DESCRIPTION



[0015] Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure. For purposes of explanation and illustration, and not limitation, a partial view of an exemplary embodiment of an additive manufacturing device in accordance with the disclosure is shown in Fig. 1 and is designated generally by reference character 100. Other embodiments of additive manufacturing devices in accordance with the disclosure, or aspects thereof, are provided in Figs. 2-3, as will be described. The systems and methods described herein can be used to improve build quality in additive manufacturing processes such as laser powder bed fusion (LPBF).

[0016] The additive manufacturing device 100 includes a build platform 102 a portion of which is a build area 104 for additively manufacturing a part 106. A recoater 108 is operatively connected to the build platform 102 to move relative to the build platform 102 to coat unfused powder onto a build, e.g., the part 106 in progress, on the build platform 102.

[0017] With reference now to Fig. 2, the recoater 108 includes a recoater mount 110 defining a length-wise receptacle 112 therein. A recoater blade 114 is seated in the receptacle 112. The recoater blade 114 is of a relatively soft material for soft-recoater additive manufacturing. For example, polymeric 0.25 inch (6.35 mm) O-ring stock material, or any other suitable material can be used. The recoater mount 110 is of a relatively hard material, such as stainless steel, tungsten carbide, nylon 12, or the like.

[0018] Referring again to Figs. 1 and 2 a blade reel system 116 is operatively connected to the recoater 108 to replace the recoater blade 114 (shown in Fig. 2) in the receptacle 112 during a build on the build platform 102. The blade reel system 116 is mounted stationary relative to the build platform 102 outside of the build area 104. The blade reel system 116 includes a first feed reel 118 configured to feed fresh recoater blade material 120 (shown in Fig. 2) into the receptacle 112, replacing used recoater blade material 122 as the fresh recoater blade material 120 is reeled in the direction F into the receptacle 112. A first up take reel 124 is included opposite the first feed reel 118 for taking up the used recoater blade material 122. The blade reel system 116 includes a cutter and loader 126 operatively connected to remove used recoater blade material 122 (shown in Fig. 2), load the fresh blade material 120 in place, and cut it after it is loaded into the receptacle 112 to free the recoater 108 from the blade reel system 116 so the recoater 108 can recoat the build area 104 using the fresh blade material 120.

[0019] As shown in Fig. 1, the recoater 108 is shown recoating the build area 104 while approaching the first feed reel 118 and up take reel 124. The blade reel system 116 optionally includes a second feed reel 128 and a second up take reel 130 at an opposite end of the build area 104 from the first feed reel 118 and first up take reel 124. After the first feed reel and uptake reel 118, 124 replace the recoater blade 114, the recoater 108 can approach the second feed and up take reels 128, 130, which similarly replace the recoater blade 114 and cut the recoater 108 loose with a cutter 132. In this manner, the recoater 108 can recoat the build area 104 with each pass in ether recoat direction R, as indicated with the large double arrow in Fig. 1. Each pass can use a fresh recoater blade 114. As the recoater 108 is reloading at the blade real system 116 at either end of the build area, the laser 134 can selectively fuse part of the last layer of powder from recoating to the part 106.

[0020] With reference now to Fig. 3, another exemplary embodiment of a blade reel system 216 is shown. The blade reel system 216 is mounted to the recoater 108 for movement together with the recoater 108 relative to the build platform 102. The blade reel system 216 includes a supply reel 218 and a take up reel 214 on opposite ends of the recoater mount 110. The supply reel 218 and take up reel 214 are configured to reel blade material 120 through the receptacle 112 (as shown in Fig. 2) as the recoater 108 passes over the build area 104. This movement can be intermittent or continuous as needed to maintain a fresh recoater blade 114. It is also contemplated that the supply reel 218 and the take up reel 214 can reel the blade material 120 back and forth in the direction F as the recoater 108 passes over and recoats the build area 104.

[0021] Each of the reels 118, 124, 128, 130, 218, 214 of Figs. 1 and 2 can include a spool magazine 136 with adequate capacity to hold a reel of recoater blade material 120 sufficient to completely replace the recoater blade material 120 with each pass of the recoater 108 over the build area 104 during a build. Some applications may not need complete replacement of the recoater blade material 120 with each pass, in which case less frequent replacement can be used. This system allows for replacement of the blade material 120 during a build each time it the recoater blade 114 becomes degraded to a point where further use would risk a build failure.

[0022] A method of additive manufacturing includes recoating powder over a build area (e.g. build area 104) using a recoater (e.g. recoater 108) and selectively fusing a portion of the powder to a build in the build area as indicated schematically in Figs. 1 and 3 with the laser 134. The method includes replacing a recoater blade (e.g. recoater blade 114) in the recoater with the build in progress, and repeating recoating, selectively fusing, and replacing the recoater blade until the build is complete (e.g., until part 106 is finished).

[0023] The methods and systems of the present disclosure, as described above and shown in the drawings, provide for additive manufacturing with superior properties including reduced build failures and more consistent build properties and quality throughout a build due to a fresh recoater blade replenished on the fly during builds. While the apparatus and methods of the subject disclosure have been shown and described with reference to the exemplified embodiments, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the scope of the subject disclosure.


Claims

1. An additive manufacturing device (100) comprising:

a build platform (102);

a recoater (108) operatively connected to the build platform (102) to move relative to the build platform (102) to coat unfused powder onto a build on the build platform (102), wherein the recoater includes a recoater mount (110) defining a length-wise receptacle (112) therein, and a recoater blade (114) seated in the receptacle (112); and

a blade reel system (116) operatively connected to the recoater (108) to replace the recoater blade (114) in the receptacle (112) during a build on the build platform (102).


 
2. The device as recited in claim 1, wherein the blade reel system (116) is mounted stationary relative to the build platform (102) outside of a build area (104).
 
3. The device as recited in claim 2, wherein the blade reel system (116) includes a reel (124)configured to feed fresh recoater blade material into the receptacle (112), replacing used recoater blade material.
 
4. The device as recited in claim 3, wherein the blade reel system (116) includes a cutter operatively connected to cut fresh blade material to free the recoater (108) from the blade reel system (116) to recoat the build area (104) using the fresh blade material.
 
5. The device as recited in claim 1, wherein the blade reel system (116) is mounted to the recoater (108) for movement together with the recoater (108) relative to the build platform (102).
 
6. The device as recited in any preceding claim, wherein the blade reel system (116) includes a supply reel and a take up reel on opposite ends of the recoater mount (110), wherein the supply reel (218) and take up reel (214) are configured to reel blade material through the receptacle as the recoater (108) passes over the build area (104).
 
7. The device as recited in claim 6, wherein the supply reel (218) and the take up reel (214) are configured to reel the blade material back and forth as the recoater passes over the build area (104).
 
8. The device as recited in any preceding claim, wherein the blade reel system (116) includes a magazine with adequate capacity to hold a reel of recoater blade material sufficient to completely replace the recoater blade material with each pass of the recoater over the build area (104) during a build.
 
9. A method of additive manufacturing comprising:

recoating powder over a build area (104) using a recoater (108);

selectively fusing a portion of the powder to a build in the build area (104);

replacing a recoater blade (114) in the recoater (108) with the build in progress; and

repeating recoating, selectively fusing, and replacing the recoater blade (114) until the build is complete.


 
10. The method as recited in claim 9, wherein replacing a recoater blade (114) includes moving the recoater (108) beyond the build area (104) to a blade reel system (116).
 
11. The method as recited in claim 10, wherein replacing the recoater blade (114) includes reeling fresh recoater blade material into a receptacle (112) of the recoater (108).
 
12. The method as recited in claim 11, further comprising cutting the fresh blade material to free the recoater to recoat the build area using the fresh blade material.
 
13. The method as recited in any of claims 9 to 12, wherein replacing a recoater blade in the recoater (108) includes moving a blade reel system together with the recoater and reeling blade material through the receptacle (112) as the recoater (108) passes over the build area (104).
 
14. The method as recited claim 13, wherein reeling blade material through the receptacle (112) as the recoater (108) passes over the build area includes reeling the blade material back and forth in the recoater receptacle (112) as the recoater (108) passes over the build area.
 
15. The method as recited in any of claims 9 to 14, wherein replacing the recoater blade includes completely replacing the recoater blade (114) for each recoating pass of the recoater (108) over the build area (104).
 




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