IntelligentensingaterialsLab., Depatent of Nano - PDF document

FundamentaO of ³Cavitation PeeninJ´ is now on YouTube. 3 min. Invited review paper about ³cavitation peeninJ´ is avaiOabOe on foOOowinJ URL as OPEN ACESS JournaO. http://www.oldcitypublishing.com/wp-content/uploads/2017/11/IJPSTv1n1p3-60Soyama.pdf H. Soyama, ³Key Factors and AppOications of Cavitation PeeninJ´ International Journal of Peening Science and Technology VoO. 1 2017, pp. 3-60. Cavitation S PeeningŠ is a peening methodcavitation impacts in the same way as shot peening to improve fatigue strength and/or to introduce compressive residual stress. The peening method using cavitation impact is called “cavitation shotless peening (CSP)”, as shots are not required (see Fig. 1). In the case of cavitationshotless peening, cavitation is generated by cavitating jetis phase change phenomena fromliquid-phase to gas-phase. It is similar to boiling, but, in the case of cavitation, liquid-phase becomes gas-phase by decrease of static pressure until saturated vapor pressure due to increase of flow velocity (see Fig. 2). When the static pressure is increased by decrease of the flow velocity, the cavitation bubble is collapsed. At the cavitation bubble collapse, a part of the bubble is deformed and a micro-jet is produced (see Fig. 3). As the speed of the micro-jet is about 1,500 m/s, the micro-jet produces plastic deformation pit on the solid surface. After the cavitation bubble shrink, the cavitation bubble rebounds. At the rebound, shock wave is produced. The shock wave also produces plastic deformation (see Fig. 3). is a jet with cavitation bubbles produced by injecting a high-speed water jet into water (see Fig. 4). The cavitation bubbles take place in the low pressure region of vortex core in the shear layer around the jet. The vortex cavitations combine and big cavitation cloud is produced. When the cavitation cloud hit the surface, cavitation impacts are produced at bubble collapses. Soyama successfully produced cavitating jet in air by injecting a high-speed water jet into a low-speed water jet. H.Soyama, Trans. ASMEJournal of Fluids Engineering, Vol. 127, No. 4, 2005, pp. 1095-1101. Cavitation S PeeningŠ Cavitation constzgp=++rr Head Static pressure Bernoulli¶s equation Phase diagram of water and Bernoulli¶s equation Micro-jet Shock waveCavitation bubble Rebound In Water High speed Low pressure region] Low speed Highpressure region] Fig. 3 Schematic diagram of cavitation bubbleCavitating jet Fig. 4 Schematic diagram and photo of cavitating jetSchematic diagram Cavitating jet in waterCavitatin Shotless Shot Cavitating Jet avitationImpact ― Improvement of FatiJue StrenJtK Cavitation S PeeninJ® improves tKe fatiJue strenJtK of Jear made of carburi]ed cKromium moOybdenum steeO . It aOso enKances tKe fatiJue strenJtK of carburi]ed cKromium moOybdenum SCM420* and , aOuminum aOOoy AC4CH-T6*, DuraOumin, maJnesium aOOoy, stainOess steeO, siOicon manJanese steeO and otKer materiaOs. H.Soyama and Y.Sekine, ³SustainabOe Surface Modification UsinJ Cavitation Impact for EnKancinJ FatiJue StrenJtK Demonstrated by a Power CircuOatinJ-Type *ear Tester,´ International Journal of Sustainable Engineering, VoO. 3, No. 1, 2010, pp. 25 - 32. 300350400450500 FiJ. 5 Improvement of fatiJue strenJtK of Jear demonstrated usinJ a power circuOatinJ type Number of cycOes to faiOure Cavitation 700009001000 Not peened SP2 CSP AmpOitude of bendinJ stressMPa 10 10 cOes to faiOure FiJ. 6 curve of rotatinJ bendinJ fatiJue test Carburi]ed SCM420* 700009001000 CSP AmpOitude of bendinJ stressMPa cOes to faiOure FiJ. 7 curve of rotatinJ bendinJ fatiJue test Carburi]ed SCM 120160200Not peenedAmpOitude of bendinJ stressMPa FiJ.  curve of rotatinJ bendinJ fatiJue test AC4CH-T6* ― Peened Surface Cavitation S PeeninJ® introduces compressive residuaO stress witK a considerabOe Oess surface rouJKness compared to tKat from sKot peeninJ see FiJs. 9 and 10. IndividuaO pit induced by Cavitation S PeeninJ® does not Kave sKarp tip up around tKe pit, compared to a pit induced by baOO indentation at nearOy constant voOume and deptK see FiJ. 11. It is very sKaOOow compared to tKe pit at constant deptK of pOastic deformation area see FiJ. 12. H.Soyama, D.O.Macodiyo and S.MaOO, ³Compressive ResiduaO Stress into Titanium AOOoy UsinJ Cavitation SKotOess PeeninJ MetKod,´ Tribology Letters, VoO. 17, No. 3, 2004, pp. 501 - 504. H.Soyama, ³Introduction of Compressive ResiduaO Stress UsinJ a CavitatinJ Jet in Air,´ Trans. ASME, Journal of Engineering Materials and Technology CSP SP -1200-00-400400050100150200 Distance from tKe surfaceResiduaO stress Not peened CSP FiJ. 9 Peened surface and residuaO stress Ti-6AO-4V* -100002040600 CSP SP Distance from tKe surfaceResiduaO stress CSP FiJ. 10 Peened surface and a CSP b BaOO indentation FiJ. 11 Aspect of pit* VoOume 2.3 mm FiJ. 12 DeptK and pOastic deformation area* ― SinJuOarity of CSP FuOO widtK at KaOf ma[imum of diffracted X-ray profiOe from aOOoy tooO steeO peened by Cavitation S PeeninJ® becomes narrower tKan tKat of not peened specimen see FiJ. 13. TKe ratio of arc KeiJKt between N-JaJe and A-JaJe of AOmen strip peened by Cavitation S PeeninJ® is different from tKat of sKot peeninJ see FiJ. 14. PeeninJ Effect Cavitation S PeeninJ® can be appOied for suppression of cracks induced by Keat cycOe see FiJ. 15, reOief of micro strain see FiJ. 16, peen forminJ see FiJ. 17, and enKancement of CVT eOement see FiJ. 1. H.Soyama, ³Macro and Micro Strain in PoOycrystaOOine MetaO ControOOed by Cavitation SKotOess PeeninJ,´ Metal Finishing , VoO. 7, November issue, 2006, pp. 4 - 50. H.Soyama, H. Kumano, K. Saito and M. Saka, ³EvaOuation of PeeninJ Intensity of Cavitation SKotOess PeeninJ by UsinJ AOmen Strip,´ Proceedings of APCFS & ATEM '01, 2001, pp. 1047 - 1050. 11 H.Soyama, ³Surface Modification of MetaOOic MateriaOs by UsinJ StrinJ Cavitation,´ Journal of Japan Society forHeat Treatment, VoO. 4, No. 2, 200, pp. 74 - 7. H.Soyama and N.Yamada, ³ReOievinJ Micro-Strain by IntroducinJ Macro-Strain in a PoOycrystaOOine MetaO Surface by Cavitation SKotOess PeeninJ,´ Materials Letters, VoO. 62, No. 20, 200, pp. 3564 - 3566. H.Soyama and K. Saito, ³Peen ForminJ UsinJ a CavitatinJ Jet in Air,´ Proceedings of Pacific Rim International Conference on Water Jetting Technology, 2003, pp. 429 - 436. 10210410610ReOative intensity of X-ray Diffraction anJOe 2 SP FiJ. 13 Diffracted surface of aOOoy tooO steeO SKD61* 0.000.040.00.12024610ProcessinJ time s/mm Micro-strain 1 1 0 2 0 0 2 1 1 FiJ. 16 ReOief of micro strain by CSP* 0.1.01.21.41.61. Not peened 10Number of cycOe to faiOure NormaOi]ed bendinJ force FiJ. 1 curve of CVT eOements* 㻜.㻞㻜.㻠㻜.㻢㻜.8㻜㻡㻝㻜㻝㻡ProcessinJ time s/mm FiJ. 17 Curvature induced by CSP* = 30 MPa 20 MPa 㻜㻞㻜㻜㻠㻜㻜㻢㻜㻜8㻜㻜*as nitridunJ  SP *as nitridinJ  HSP *as nitridinJ  CSP FiJ. 15 Number of cracks after Keat cycOe test*Number of cracks FiJ. 14 ReOation on arc KeiJKt between N-and A-JauJe, and surface of AOmen strip* NAdHdH NAdHdH SP =0.15 mm CSP a Not peened 0.000.050.100.150.200.000.100.200.300.40Arc KeiJKtArc KeiJKt IntelligentensingaterialsLab., Department of NanomecKanics, ToKoku University Cavitation S PeeninJ® SeveraO Types of CavitatinJ Jets and Water Jet H.Soyama, Trans. ASME, Journal of Engineering Materials and Technology, VoO. 126, No. 1, 2004, pp. 123 - 12. H.Soyama, Trans. ASME, Journal of Fluids Engineering, VoO. 127, No. 4, 2005, pp. 1095- 1101. H.Soyama, Journal of Materials Science, VoO. 42, No. 16, 2007, pp. 663-6641. H.Soyama et aO., ISIJ International, VoO. 4, No. 11, 200, pp. 1577-151. H.Soyama et aO., Surface & Coatings Technology, VoO. 205, 2011, pp. 3167-3174. H.Soyama and O.Takakuwa, Journal of Fluid Science and Technology, VoO. 6, No. 4, 2011, pp. 510-521. CavitatinJ Met Water Met CavitatinJ Met Water Met witK associated CavitatinJ Met witK associated water Met Water Met witK associated CavitatinJ Met witK pressuri]ed cKamber Water Met witK associated Water Met in airFiJ. 1 Erosion pattern of severaO types of cavitatinJ Mets and3, 4, *5, *6 At cavitation peeninJ, tKere is no Ked before erosion takes pOace. 0.600msFiJ. 2 CKanJinJ appearance of a cavitatinJ Met in air witK tim 250300350400 Number of cycOes to faiOure AmpOitude of bendinJ stress CavitatinJ Met in air Not peened CavitatinJ Met in water CavitatinJ Met in water FiJ. 3 300350400450500AmpOitude of bendinJ stress MPa Number of cycOes to faiOure Not peened CavitatinJ Met in water witK associated water Met FiJ. 4 Department of Nanomechanics,TohokuUniversity Severeerosivevorte[cavitation RinJ vorte[ cavitation COoudcavitation Vorte[cavitationinsKearOayerImpinJinJsurface waterMet ScKematicdiaJramofcavitatinJMetHiJKspeedpKotoJrapKofcavitatinJMettakenbySoyamaWATER ，J. Soc. Mater. Sci., Japan,199, pp. 31-37. Department of Nanomechanics,TohokuUniversity 0100200300400 DevelopingregionOfvortexcavitationCollapsingregionofvortexcavitationCOoudcavitation RinJerosionVorte[cavitation InWaterwater Collapsingregionofvortexcavitation Inverse of curvature 1/NormaOi]ed standoff distance CavitationimpactsCavitationimpactsMechanicalEngineeringReviewVoO.2,No.1Jan.2015,PaperNo.14-00192,pp.1-20. Water Jet PeeninJ StandoffdistanceStandoffdistance PotentiaOcore = inMection pressure [ fOow rateisnearOy equaO. sKotimpactsareused.Cavitationimpactsareused Department of Nanomechanics,TohokuUniversity ≧1.8 ߪ Cavitation PeeninJWater Jet PeeninJMechanicalEngineeringReviewVoO.2,No.1Jan.2015,PaperNo.14-00192,pp.1-20. Cavitationnumber:sInMectionpressureoftKeMet:Downstreampressureofno]]Oe:Vaporpressure: Water Jet PeeninJsKotimpactsareused.Cavitationimpactsareused Department of Nanomechanics,TohokuUniversity In order to avoid tKe , tKe Oow inMection pressure and OarJe no]]Oe si]e is better tKan tKe KiJK inMection pressurefor cavitation peeninJ. Standoff distance pvpp Peened d Standoff distance pvpp Peened H. Soyama and O. Takakuwa, Journal of Fluid Science and Technology, VoO. 6 2011, pp. 510-521. -300-200-1000200400600DeptK from tKe surface Tension = 300 MPa, = 0.35 mm = 30 MPa, Jet power isnearOy equaO.