DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Status
A preliminary amendment, filed 6/27/2023, is acknowledged. Claims 3-5, 7-8, and 11-12 are amended. Claims 1-12 are currently pending.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-12 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 is drawn to a method of laser powder bed fusion additive manufacturing comprising “performing laser melting of layers of a powder bed of steel powder,” thus, requiring heating at least portions of the steel powder bed to a melting temperature of steel. Claim 1 also requires, however, “wherein a temperature of the powder bed is below 220°C.” One of ordinary skill in the art would recognize that the melting temperature of the claimed steel composition would greatly exceed 220°C. Therefore, the claim is indefinite because it is unclear what step, for example, when in the method sequence or where in the powder bed, the “temperature of the powder bed is below 220°C” occurs during the claimed method, as the entirety of the powder bed could not remain at this temperature while carrying out the other claim limitations. Claims 2-12 are indefinite based on their dependency.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1 and 3-7 are rejected under 35 U.S.C. 103 as being unpatentable over Ognianov et al. (WO 2019/233962)(machine translation provided).
With respect to Claim 1, Ognianov teaches a method of laser powder bed fusion additive manufacturing, the method comprising performing a plurality of steps of selectively melting and fusing, with a laser, portions of powder layers in a powder bed, the method taking place in a protective atmosphere, such as nitrogen, wherein the powder bed is preheated to a temperature of 200-450°C, and wherein the powder comprises a steel powder with a composition, by weight%, as follows:
Claim 1
Ognianov
Cr
3-7
4.2-5.0
Mo
2-5
2.8-3.3
V
0.2-0.7
0.41-0.69
Si
≤ 0.7
0.1-0.3
Mn
≤ 1
0.1-0.4
C
≤ 1.5
0.45-0.56
Fe
balance
balance
Compositional ranges including zero (e.g. the claimed ranges of Si, Mn, and C) are interpreted as optional elements. Thus, Ognianov teaches a method of additive manufacturing with a steel powder having a composition overlapping or falling within each of the instantly claimed ranges and wherein the powder bed is preheated to a temperature overlapping the instantly claimed range.
It would have been obvious to one of ordinary skill in the art to select from the portions of the overlapping compositional and temperature ranges. Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
With respect to respect to Claims 3-6, Ognianov teaches preheating the powder bed to a temperature of 200-450°C, overlapping the instantly claimed ranges. (see rejection of claim 1 above). Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
With respect to claim 7, Ognianov teaches wherein the method of additive manufacturing is carried out in a protective atmosphere of nitrogen, interpreted to meet the recited atmosphere consisting essentially of nitrogen. (pg. of translation).
Claim(s) 8-11 are rejected under 35 U.S.C. 103 as being unpatentable over Ognianov et al. (WO 2019/233962)(machine translation provided), as applied to Claim 1 above, in view of Buller et al. (US 9962767).
With respect to Claims 8-10, Ognianov teaches wherein the method of additive manufacturing is carried out in a protective atmosphere of nitrogen (pg. of translation), but is silent as to a further protective gas as respectively required in claims 8, 9, and 10.
Buller teaches a method of additive manufacturing comprising controlling the additive manufacturing chamber to have an inert gas atmosphere of, for example, nitrogen, argon, helium, and mixtures thereof. (col. 102, lns. 10-26).
It would have been obvious to one of ordinary skill in the art to substitute the inert atmosphere of Ognianov for an inert gas atmosphere comprising a combination of inert noble gases, such as nitrogen and argon, as taught by Buller, in order to obtain a high purity inert atmosphere for additive manufacturing and having the additional benefit of flexibility by using a combination of inert gases.
With respect to Claim 11, Ognianov teaches wherein the method of additive manufacturing is carried out in a protective atmosphere of nitrogen (pg. of translation), but is silent as to an oxygen concentration in the atmosphere.
Buller teaches a method of additive manufacturing comprising controlling the additive manufacturing chamber to have an inert gas atmosphere with high purity gas and comprising, for example, 2 ppm oxygen or less. (col. 102, lns. 10-26).
It would have been obvious to one of ordinary skill in the art to modify the method of Ognianov, to select a high purity inert gas atmosphere having an oxygen content of 2 ppm or less, as taught by Buller, in order to prevent unwanted contamination and/or oxidation of the additively manufactured part.
Claim(s) 12 is rejected under 35 U.S.C. 103 as being unpatentable over Ognianov et al. (WO 2019/233962)(machine translation provided), as applied to Claim 1 above, in view of Mattes et al. (US 2021/0245251).
With respect to Claim 12, Ognianov teaches wherein performing laser melting of layers of the steel powder bed comprises controlling a laser to direct the laser to selected areas of successive powder layers sufficient to melt desired portions and thus, interpreted to comprise a set of exposure parameters (see pgs. of translation); however, the reference is silent as to whether the exposure parameters are such that melt pools are formed in transition or conduction mode.
Mattes teaches a method of additive manufacturing comprising laser powder bed fusion, wherein the exposure parameters of the laser are tailored to form melt pools in conduction mode. (para. 5, 16, 19, 30). Mattes teaches that by tailoring the laser exposure parameters to achieve this mode, higher penetration depth, reduced evaporation, and improved additive manufacturing may be achieved. (para. 5, 140, 162).
It would have been obvious to one of ordinary skill in the art to modify the method of Ognianov to control the laser exposure parameters such that melt pools are formed in conduction mode, as taught by Mattes, in order to obtain higher laser/melt pool penetration depth, reduced evaporation, and improved additive manufacturing quality.
Claim(s) 1-11 are rejected under 35 U.S.C. 103 as being unpatentable over Fukuzawa et al. (US 2021/0040591) in view of Gritckevich et al. (WO 2018/236243) and Buller et al. (US 9962767).
With respect to Claim 1, Fukuzawa teaches a method of laser powder bed fusion additive manufacturing, the method comprising performing a plurality of steps of selectively melting and fusing, with a laser, portions of powder layers in a powder bed, and wherein the powder comprises a steel powder with a composition, by weight%, as follows (para. 8-10, 18-35):
Claim 1
Fukuzawa
Cr
3-7
3.0-6.0
Mo
2-5
0.5-3.5*
V
0.2-0.7
0.5-3.5
Si
≤ 0.7
≤ 2.0
Mn
≤ 1
≤ 1.5
C
≤ 1.5
0.3-0.5
Fe
balance
balance
Other
-
Mo: 0.5-3.5*
P: ≤ 0.05
S: ≤ 0.05
*wherein Mo and/or W are included, such that Mo+1/2W) is 0.5-3.5
Compositional ranges including zero (e.g. the claimed ranges of Si, Mn, and C) are interpreted as optional elements. Thus, Fukuzawa teaches a method of additive manufacturing with a steel powder having a composition overlapping or falling within each of the instantly claimed ranges. It would have been obvious to one of ordinary skill in the art to select from the portions of the overlapping compositional ranges. Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
Fukuzawa is silent as to wherein the temperature of the powder bed is preheated to a temperature below 220°C.
Gritckevich teaches a method of selective laser sintering or melting (SLM/SLS) of a metal powder, and thus, comprising powder bed fusion, wherien the surface of the powder bed is heated (i.e. preheated) using infra-red heating to a desired temperature of up to 900°C. (pg. 1, lns. 1-26; pg4, ln. 14 to pg. 5, ln. 2). The reference teaches that preheating the powder of the powder bed has the benefit of reducing the thermal gradients and slowing down the cooling rates within heat affected zone lowering susceptibility for residual stress formation and cracking during solidification. (pg. 4, lns. 4-13). Thus, Gritckevich teaches the benefit of preheating a metal powder bed in a powder bed fusion method in a temperature range of ambient up to 900°C.
Thus, Fukuzawa and Gritckevich are both drawn to powder bed fusion SLM methods of additive manufacturing with a metal powder. It would have been obvious to one of ordinary skill in the art to modify the method of Fukuzawa to preheat the powder bed to a temperature of up to 900 C, as taught by Gritckevich, in order to reduce the thermal gradients and slow down the cooling rates within heat affected zone lowering susceptibility for residual stress formation and cracking during solidification in the method. Additionally, it would have been obvious to one of ordinary skill in the art to select from the portions of the overlapping temperature ranges. Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
Finally, Fukuzawa is silent as to carrying out the method in a protective atmosphere comprising nitrogen.
Buller teaches a method of additive manufacturing comprising controlling the additive manufacturing chamber to have an inert gas atmosphere of, for example, nitrogen, argon, helium, and mixtures thereof. (col. 102, lns. 10-26).
It would have been obvious to one of ordinary skill in the art to modify the method of Fukuzawa in view of Gritckevich to provide a protective atmosphere of at least nitrogen, as taught by Buller, in order to obtain a high purity inert atmosphere for additive manufacturing reducing contamination and/or oxidation of the metal powder and additively manufactured part.
With respect to respect to Claims 2-6, Fukuzawa in view of Gritckevich and Buller teach preheating the powder bed to a temperature of up to 900°C, overlapping the instantly claimed ranges. (see rejection of claim 1 above). Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
With respect to claim 7, Fukuzawa in view of Gritckevich and Buller teach wherein the method of additive manufacturing may be carried out in a protective atmosphere of nitrogen, interpreted to meet the recited atmosphere consisting essentially of nitrogen. (see rejection of claim 1 above).
With respect to Claims 8-10, Fukuzawa in view of Gritckevich and Buller teach wherein the method of additive manufacturing is carried out in a protective atmosphere of one or more of nitrogen, argon, and helium (see rejection of claim 1 above). Accordingly, it would have been obvious to one of ordinary skill in the art to select a combination of inert noble gases, such as nitrogen and argon, as taught by Buller, in order to obtain a high purity inert atmosphere for additive manufacturing and having the additional benefit of flexibility by using a combination of inert gases.
With respect to Claim 11, Buller teaches a method of additive manufacturing comprising controlling the additive manufacturing chamber to have an inert gas atmosphere with high purity gas and comprising, for example, 2 ppm oxygen or less. (col. 102, lns. 10-26). It would have been obvious to one of ordinary skill in the art to select a high purity inert gas atmosphere having an oxygen content of 2 ppm or less, as taught by Buller, in order to prevent unwanted contamination and/or oxidation of the additively manufactured part.
Claim(s) 12 is rejected under 35 U.S.C. 103 as being unpatentable over Fukuzawa et al. (US 2021/0040591) in view of Gritckevich et al. (WO 2018/236243) and Buller et al. (US 9962767), as applied to Claim 1 above, in view of Mattes et al. (US 2021/0245251).
With respect to Claim 12, Fukuzawa teaches wherein performing laser melting of layers of the steel powder bed comprises controlling a laser to direct the laser to selected areas of successive powder layers sufficient to melt desired portions and thus, interpreted to comprise a set of exposure parameters (see, e.g., para. 50; Table 2, teaching laser parameters); however, the reference is silent as to whether the exposure parameters are such that melt pools are formed in transition or conduction mode.
Mattes teaches a method of additive manufacturing comprising laser powder bed fusion, wherein the exposure parameters of the laser are tailored to form melt pools in conduction mode. (para. 5, 16, 19, 30). Mattes teaches that by tailoring the laser exposure parameters to achieve this mode, higher penetration depth, reduced evaporation, and improved additive manufacturing may be achieved. (para. 5, 140, 162).
It would have been obvious to one of ordinary skill in the art to modify the method of Fukuzawa in view of Gritckevich and Buller to control the laser exposure parameters such that melt pools are formed in conduction mode, as taught by Mattes, in order to obtain higher laser/melt pool penetration depth, reduced evaporation, and improved additive manufacturing quality.
Conclusion
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/JOHN A HEVEY/Primary Examiner, Art Unit 1735