"HIP Modeling Methodology Based on the Inherent Process Anisotropy

Transcription

1 "HIP Modeling Methodology Baed on the Inherent Proce Aniotropy Victor Samarov, Vaily Golovehkin, Charle Barre, ( LNT PM, Syneretch P/M, Inc., 65 Monarch treet, Garden Grove CA, USA, 984) Abtract The net hape HIP approach i baed on computer program with embedded engineering model of powder conolidation, hrinkage and urface formation that ue the computer aided deign (CAD) of the part needed and of the HIP tooling. Denification pattern during HIP, which i the key to net hape technology i determined by the capule and powder material rheology and i, at the initial tage, controlled by the capule platic tiffne. However, dilatometric experiment on HIP of capule with powder revealed that even at the final tage of denification when the capule i pliable, deformation are not uniform and follow the dominating radial or axial component though the preure i iotatic and of uniform denity. Deformation pattern i determined by a form of deformation hitory, uch that ome aniotropy generated during thi hitory become inherent and thi, in turn, control the proce of hrinkage even under uniform preure of HIP. Following thi approach, the equation decribing the material model during HIP have been modified and appropriate experiment carried out for their parametrical identification. Aniotropic behavior of powder material during net hape HIP conolidation, dicovered during pecial experiment with porou ample, wa demontrated experimentally and by introducing an aniotropy module within the entire HIP proce numerical model. Baic Hypothee and Equation The advancement toward net hape HIP i provided by the proce modeling and HIP tooling deign. The propoed tep to highly deirable net hape product are improvement to exiting proce model ued to deign HIP tooling. The more advanced modeling mut fully account for the evolution of material propertie during HIP cycle. In other word, the powder rheology may depend on the inherent aniotropy caued by the evolution of pore during conolidation. Thee mechanim provide additional control of capule/powder hrinkage during HIP. To introduce inherent aniotropy caued in HIP triggered by initial difference in capule tiffne and then developed due to the pore evolution, it i neceary to accept the following baic hypothee.. Hypothei N. where ε ij There exit a platic potential, i.e., there exit a yield urface, f ( ij, µ k ) 0, λ f and µ k -are ome kinetic parameter. ij. Hypothei N. Ditribution A. Approved for public releae; ditribution unlimited.

2 Report Documentation Page Form Approved OMB No Public reporting burden for the collection of information i etimated to average hour per repone, including the time for reviewing intruction, earching exiting data ource, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comment regarding thi burden etimate or any other apect of thi collection of information, including uggetion for reducing thi burden, to Wahington Headquarter Service, Directorate for Information Operation and Report, 5 Jefferon Davi Highway, Suite 04, Arlington VA Repondent hould be aware that notwithtanding any other proviion of law, no peron hall be ubject to a penalty for failing to comply with a collection of information if it doe not diplay a currently valid OMB control number.. REPORT DATE APR 005. REPORT TYPE. DATES COVERED - 4. TITLE AND SUBTITLE HIP Modeling Methodology Baed on the Inherent Proce Aniotrophy 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Victor Samarov; Vaily Golovehkin; Charle Barre 5d. PROJECT NUMBER OSDB 5e. TASK NUMBER R4PT 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Synertech P/M, Inc.,65 Monarch St.,Garden Grove,CA, PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 0. SPONSOR/MONITOR S ACRONYM(S). DISTRIBUTION/AVAILABILITY STATEMENT Approved for public releae; ditribution unlimited. SUPPLEMENTARY NOTES. SPONSOR/MONITOR S REPORT NUMBER(S) 4. ABSTRACT The "net hape" HIP approach i baed on computer program with embedded engineering model of powder conolidation, hrinkage and urface formation that ue the computer aided deign (CAD) of the part needed and of the HIP tooling. Denification pattern during HIP, which i the "key" to "net hape" technology i determined by the capule and powder material rheology and i, at the initial tage, controlled by the capule platic tiffne. However, dilatometric experiment on HIP of capule with powder revealed that even at the final tage of denification when the capule i pliable, deformation are not uniform and follow the dominating radial or axial component though the preure i iotatic and of uniform denity. Deformation pattern i determined by a form of deformation hitory, uch that ome "aniotropy" generated during thi hitory become inherent and thi, in turn, control the proce of hrinkage even under uniform preure of HIP. Following thi approach, the equation decribing the material model during HIP have been modified and appropriate experiment carried out for their parametrical identification. Aniotropic behavior of powder material during "net hape" HIP conolidation, dicovered during pecial experiment with porou ample, wa demontrated experimentally and by introducing an aniotropy module within the entire HIP proce numerical model. 5. SUBJECT TERMS 6. SECURITY CLASSIFICATION OF: 7. LIMITATION OF ABSTRACT a. REPORT unclaified b. ABSTRACT unclaified c. THIS PAGE unclaified 8. NUMBER OF PAGES 8 9a. NAME OF RESPONSIBLE PERSON

3 The hape (the equation) of the yield urface depend only on the current value of accumulated deformation, not on the proce hitory (trajectory). It mean that the urface equation i a follow: f ( ij, ε ij ) 0.. Hypothei N. The initial tate of the powder material i iotropic. It mean that in the principal ytem axe of deformation tenor the following equation i valid: f f ( ij, ε, ε,, ε) 0. We alo preume that the equation for the urface can be preented a a quadratic form. Auming all of thi, the equation for the yield urface can be preented a: f g + g + g + g + g + g + d + d + d where the function g, d are the function of ε, ε, ε. Let u conider an experiment on axiymmetric upetting of a cylindrical pecimen with the denity along the axi. Then ε ε ε, ε ε, ε + ε e Then the yield urface equation can be preented a follow: g ( ε, ) + g( ε, ) + g ( ε, ) +ψ ( ε, ) +ψ ( ε, ) + + ψ ( ε, ) + d ( ε, ) + d ( ε, ) + d ( ε, ) Then, if we conider upetting a pecimen cut-off at the angle ϕ to the axi () in the plane perpendicular to the axi () the reult hould not depend on the value of ϕ. Let u deignate upetting tre a. Then: 0, 0, co ϕ, in ϕ, coϕ inϕ. If we ubtitute thee value in the equation for the yield urface, we hall obtain the following: 4 4 g ε, )(co ϕ + in ϕ) + ψ ( ε, )in ϕ co ϕ + d( ε, )in ϕ co ϕ [ ( ] or [ ] g( ε, ) + in ϕ co ϕ( ψ ( ε, ) + d( ε, ) g( ε, )) Due to the axial ymmetry, the value of doe not depend on ϕ. Then: d ( ε, ) g( ε, ) ψ ( ε, ) Where 0 ε + ε e Plan of Experiment Ditribution A. Approved for public releae; ditribution unlimited.

4 The following experiment were carried out to determine and characterize the function. There will be two type of experiment: experiment with the iotropic material (# and #) and experiment with non-iotropic material (#, #4 and #5).. Experiment #. HIP in a thin-walled ymmetrical capule with the deformation tenor being cloe to the pherical one. Then, 0 ε ε ε e A P( ), the platicity criterion will give the following relation for the two function:, ) + ψ( e, ) P. Experiment #. Uniaxial deformation (upetting) of the ample obtained in Experiment #. Then, 0, 0 and a a reult, we get the econd relation:, ) and can, therefore, determine the value for both function in the point (,e ). The value for the third function in thi point (,e ) can be derived if we conider upetting of thi iotropic material along the axi other than which lead to the following relation: de (, ), ) ψ ( e, ). Experiment #. HIP in a thick walled capule leading to practically uni-directional deformation along the axi. For thi deformation model 0 ε ε 0, ε e Letting the axial tre be я, and uing the equation for the yield urface and the condition that both of the deformation in the direction orthogonal to are equal to zero, we can get the following relation 0 for the function: g g( ε, ), ψ ψ ( ε, ) in the two point: ε 0, ε e ψ (, 0 ), ) g(, 0 ) + ψ( e, ) z 4. Experiment #4. Ditribution A. Approved for public releae; ditribution unlimited.

5 Uniaxial deformation (upetting) of the ample obtained in Experiment # in the direction of the maximal deformation. If the flow tre of upetting i, then the equation for the yield urface will provide the econd relation, enabling u to determine g g( e, ):, ) The ratio between the deformation in the direction and orthogonal direction (an analogue of ε the Poion coefficient) β will give the third relation between the function: ε ψ (, 0 ) β, ) 5. Experiment #5. Uniaxial deformation (upetting) of the ample obtained in Experiment # in the direction orthogonal to the maximal deformation. If the flow tre of upetting i, it will give the fourth relation for the function: g(, 0 ) A a reult, we can obtain the value of two function in two more point in addition to the value determined after Experiment # and #. For the third function, due to iotropic propertie in the direction orthogonal to the maximal deformation, we get the relation in the point d d( e, ) and de (, ) g( 0, ) ψ ( e, ) A a reult of the treatment of experimental data, we get the value of the firt two function in three point ( ε 0, ε e, ε e ), and for the third function, in two point (ε e, ε e ), for a given value of denity reached during HIP, i.e., to reveal the effect of deformation aniotropy. Carrying out experiment for everal HIPed denitie, it become poible to build approximation for thee three function g g( ε, ), ψ ψ ( ε, ), d d( ε, ). For the iotropic HIP model, the function of the platicity criterion depend on denity only. Actually aniotropy introduced in the propoed model i baed on the aumption of the exitence of the areal denity and i determined by the value of denity and of the normal deformation in the principal axe. Development of the Databae for Rheological Coefficient of the Aniotropic Model Five pecial et of experiment with iotatic and aniotropic loading were enviaged to Ditribution A. Approved for public releae; ditribution unlimited. 4

6 the value of the function g g( ε, ), ψ ψ ( ε, ), d d( ε, ) and of the influence coefficient β for everal HIPed denitie. Titanium powder alloy Ti-6Al-4V wa choen a a candidate to gain experience on producing complex haped component. Keep in mind that Ti-6Al-4V only howed mot of the ditortion and hard-to-predict feature for the titanium alloy rather than for Ni-bae alloy. To provide uni-axial deformation during HIP and create initial aniotropy of the deformation pattern, pecial thick walled capule with the increaed radial tiffne from mild 08 teel were deigned and manufactured to carry out parametric identification.. Experiment #. HIP in a thin-walled ymmetrical capule with the deformation tenor being cloe to the pherical one. 0 Then, ε ε ε e A P( ), the platicity criterion will give the following relation for the two function:, ) + ψ( e, ) P. Experiment #. Uniaxial deformation (upetting) of the ample obtained in Experiment #. Then, 0, 0 and a a reult, we get the econd relation:, ) and can, therefore, determine the value for both function in the point (,e ). The value for the third function in thi point (,e ) can be derived if we conider upetting of thi iotropic material along the axi other than, which lead to the following relation: de (, ), ) ψ ( e, ).. Experiment #. HIP in a thick-walled capule leading to practically uni-directional deformation along the axi. For thi deformation mode 0 ε ε 0, ε e Let the axial tre be я, then, uing the equation for the yield urface and the condition that both of the deformation in the direction orthogonal to are equal to zero, we can get the following relation for the function: g g( ε, ), ψ ψ ( ε, ) in the two point: 0 ε 0, ε e Ditribution A. Approved for public releae; ditribution unlimited. 5

7 , ) ψ (, 0 ) g(, 0 ) + ψ( e, ) z 4. Experiment #4. Uniaxial deformation (upetting) of the ample obtained in Experiment # in the direction of the maximal deformation. If the flow tre of upetting i, then the equation for the yield urface will provide the econd relation, enabling u to determine g g( e, ):, ) The ratio between the deformation in the direction and orthogonal direction ε (an analogue of the Poion coefficient) β will give the third relation between the ε function: ψ (, 0 ) β, ) 5. Experiment #5. Uniaxial deformation (upetting) of the ample obtained in Experiment # in the direction orthogonal to the maximal deformation. If the flow tre of upetting i, it will give the fourth relation for the function: g(, 0 ) A a reult, we can obtain the value of two function in two more point in addition to the value determined after Experiment # and #. For the third function, due to iotropic propertie in the direction orthogonal to the maximal deformation, we get the relation in the point d d( e, ) and de (, ) g( 0, ) ψ ( e, ) A a reult of the treatment of experimental data, we get the value of the firt two function in three point ( ε 0, ε e, ε e ), and for the third function, in two point ( ε e, ε e ) for a given value of denity reached during HIP, i.e., to reveal the effect of deformation aniotropy. Carrying out experiment for everal HIPed denitie, it become poible to build approximation for thee three function g g( ε, ), ψ ψ ( ε, ), d d( ε, ). For the iotropic HIP model, the function of the platicity criterion depend on denity only. Ditribution A. Approved for public releae; ditribution unlimited. 6

8 Actually, aniotropy introduced in the propoed model i baed on the aumption of the exitence of the areal denity and i determined by the value of denity and of the normal deformation in the principal axe. Figure and preent the reult of micro-tructural analyi of the mount taken from the ample oriented in different orthogonal direction. Thee photo definitely reveal the exitence of the areal denity phenomenon, when the deformation and denity pattern provide initial aniotropy. The reult of the compreion tet were proceed in order to be incorporated into the HIP model and to update the aniotropy module with actual data received from the experiment. x00 x00 Figure. Typical Micro-tructure of a Porou Sample in the Direction Orthogonal to Main Deformation Axi (Average Denity 80%) x00 x00 Figure. Typical Micro-tructure of a Porou Sample in the Direction of the Main Deformation Axi (Average Denity 8%) CONCLUSIONS Aniotropic behavior of Ti-6Al-4V atomized pherical powder during HIP Ditribution A. Approved for public releae; ditribution unlimited. 7

9 Conolidation, caued by the initial non-uniform capule tiffne, wa revealed during pecial experiment. The value of the flow tre of the ample cut off in the direction of the maximal deformation, proceed in Experiment #4, are about 0% higher than the flow tre of the ample cut off in the direction orthogonal to the maximal deformation proceed in Experiment #5. Potential for net hape HIP technology baed on advanced proce modeling accounting inherent proce aniotropy, to reduce cot and/or time required to produce pecific liquid rocket engine component wa analyzed. Thi development effort ha provided a general proof of viability of propoed net hape HIP technology baed on the advanced proce modeling. REFERENCES [] Dutton, R., Shamaundar, S., Defo, D., Semiatin, L., Modeling of the Hot Conolidation of Ceramic and Metal Powder, Metallurgical and Material Tranaction., 6A, 995 [] Defo, D., Dutton, R., Semiatin, L., Pieler, H., Modeling of Hot Iotatic Preing and Hot Triaxial Compaction of Ti-6-4 Powder, Acta Mater., 47. N9, 999, pp [] Dutton, R., Semiatin, L., The Effect of Denification Aniotropy on the Yield And Flow Behavior of Partially Conolidated Powder Compact, Metallurgical and Material Tranaction., 9A, May 998, pp Ditribution A. Approved for public releae; ditribution unlimited. 8