Method for characterising and monitoring the homogeneity of metal parts manufactured by laser sintering
AssigneeCommissariat A L'energie Atomique Et Aux Energies Alternatives
InventorsHicham Maskrot, Alexandre Semerok
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Abstract
A non-destructive method for characterizing and monitoring the homogeneity of metal parts which are being manufactured by sintering and comprise several distinct zones. Laser radiation is applied successively to each zone and each sintered zone is analyzed simultaneously in real time by lock-in laser-active radiometry.
Claims5
A non-destructive method for characterising and monitoring the homogeneity of a metal part manufactured by sintering including several distinct zones, wherein, upon manufacturing said part:
- a laser radiation is successively applied on each zone and an analysis of each sintered zone is simultaneously made with the laser radiation in real time by synchronous detection active laser radiometry,
- a frequency modulated heating generating at each frequency a single thermal wave is applied on each zone, and for each frequency, the phase shift between the luminous signal of the laser applied to the part and the thermal signal emitted by the part is measured in real time, and,
- the thickness L (μm) and thermal diffusivity D (m2/s) of each zone are determined by the following formulae:
- L
- =
- r
- 0
- ζ
- φ
-
- ln
-
- π
-
- φ
- min
-
- (
- 1
- )
- D
- =
- 1
- ζ
- f
-
- f
- min
-
-
- Lr
- 0
- (
- 2
- )
- where r0 is the laser beam radius at 1/e intensity;
- φmin and fmin represent the minimum phase shift and the laser beam rate respectively;
- ζφ and ζf represent known coefficients which depend on the minimum phase shift φmin and the ratio r0/L respectively,
- wherein a first zone and a second zone have different thicknesses.
A device for characterising and monitoring the homogeneity of a metal part manufactured by sintering including several distinct zones wherein a first zone and a second zone have different thicknesses, wherein the device includes a laser source adapted to successively apply on each zone a laser radiation upon manufacturing said part and to apply on each zone a frequency modulated heating generating at each frequency a single thermal wave, an infrared radiation detector adapted to sense and measure in real time the thermal radiation emitted by each zone, a synchronous detector for detecting phase shift between the luminous signal of the laser radiation and the thermal signal of the infrared radiation emitted by each zone, and means to determine the thickness L (μm) and thermal diffusivity D (m2/s) of each zone by the following formulae:
- L
- =
- r
- 0
- ζ
- φ
-
- ln
-
- 9
-
- 0
- ❘
- "\[LeftBracketingBar]"
- φ
- min
- ❘
- "\[RightBracketingBar]"
- (
- 1
- )
- D
- =
- 1
- ζ
- f
-
- f
- min
-
- L
-
- r
- 0
- (
- 2
- )
- where r0 is the laser beam radius at 1/e intensity;
- φmin and fmin represent the minimum phase shift and the laser beam rate respectively;
- ζφ and ζf represent known coefficients which depend on the minimum phase shift φmin and the ratio r0/L respectively.
Dependencies are inferred from the claim text.