Local Recrystallization Research Articles

Effects of Coating on Surface Recrystallization of DD6 Single Crystal Blades

The fully heat-treated DD6 single crystal turbine blades were treated in three ways: (1) surface grinding, without coating; (2) firstly surface grinding, then surface coated with HY3(NiCrAlY) anti-oxidation coating; (3) after surface grinding, coated surface with the bond layer of NiCrAlY and top layer of YSZ(Y2O3 stabilize ZrO2) for the double-layer thermal barrier coatings. All these three experimental blades were treated with vacuum heat-treatment at 1120°C for 4h. The effects of coating on surface recrystallization of single-crystal blades have been investigated. The results indicate that: just with surface polishing blade generated a 6~9μm thick cellular recrystallization zone on the surface. The γ' presented coarse morphology and distributed discretely within cellular, and the γ' growth direction was perpendicular to the cellular interface; blade surface coated with anti-oxidation coating after polishing formed a 3~6μm thick cellular recrystallization zone in the matrix interface. But the grain boundary was fuzzy and recrystallization morphology was incomplete; the matrix interface morphology of blade coated with thermal barrier coatings after polishing changed insignificantly, but some local cellular recrystallization was found. The results indicate that the coating changes the cellular recrystallization morphology of the original matrix of the blade, which can effectively reduce the occurrence degree of recrystallization.

Raman and fluorescence correlative microscopy in polarized light to probe local femtosecond laser-induced amorphization of the doped monoclinic crystal LYB:Eu

*yannick.petit@u-bordeaux1.fr An endless increasing number of laser/material interaction studies above laser-induced modification thresholds have been carried out over the past decade, either for undesirable laser-induced damages, for example in high power laser systems in relation with material ageing and material optical quality, or for profitable laser-induced alteration from direct laser writing (DLW) techniques. DLW is at the root of many applications such as the fabrication of micro-capillaries for micro-fluidics issues, waveguide writing, optical memories, etc... New functionalities based on enhanced optical property modifications can further be developed by tailoring the material chemical composition with photosensitive agents, in order to improve its interaction with the writing laser [1]. Thus, for the laserinduced linear properties, DLW can lead to plasmonic enhancement from nanoparticles [2], fluorescence from metallic clusters [3] or oxidation degree modifications of rare earth ions [4]. For the nonlinear properties, second-harmonic generation (either from locally buried electric field [5] or from locally laser-induced micro-crystallization [6]) or third-harmonic generation [7] can be obtained. Most of the studies are related to isotropic material modifications (density change, oxidation degree changes, local crystallization, etc...) [1] while much less refer to laser-induced modifications inside crystals, being isotropic [8] or not [9]. Still, laser-induced modifications inside a crystal matrix are promising research topics for perennial optical devices and applications, thanks to the intrinsic stability of the crystalline matrix arrangement, but also for waveguide applications for efficient laser and Raman amplification as well as for frequency conversion. Generally, laser-induced modifications lead to local index change, local melt, local amorphization or even local recrystallization, giving rise to differential optical properties with respect to the non-irradiated bulk matrix. In this work, we have studied the local modification induced by a femtosecond (fs) near infrared NIR laser on a monoclinic crystal matrix LYB, highly doped with Eu 3+ rare earth ions. Thanks to point-bypoint optical mapping in both Raman and fluorescence micro-spectroscopy in polarized light, we report on the local changes corresponding to partial amorphization of the LYB:Eu crystal, resulting to significant reshaping of the spectral properties in polarized light. The optical specificities of lowsymmetry crystal optics were properly taken into account, to provide meaningful interpretation of the modified Raman and fluorescence spectra. Strong laser-induced amorphization of the crystal matrix have been evidenced. An accurate characterization of the spectral variations of spatial distribution have shown (i) an homogeneous degree of amorphization within a volume at least two times larger than the laser-structuring voxel, and (ii) a variation of density within the amorphous region.

Coseismic recrystallization during shallow earthquake slip

Solidified frictional melts, or pseudotachylytes, remain the only unambiguous indicator of seismic slip in the geological record. However, pseudotachylytes form at >5 km depth, and there are many rock types in which they do not form at all. We performed low- to high-velocity rock friction experiments designed to impose realistic coseismic slip pulses on calcite fault gouges, and report that localized dynamic recrystallization may be an easy-to-recognize microstructural indicator of seismic slip in shallow, otherwise brittle fault zones. Calcite gouges with starting grain size −1 , and total displacements between 1 and 4 m. At coseismic slip velocities ≥0.1 m s −1 , the gouges were cut by reflective principal slip surfaces lined by polygonal grains 2 + CaO. The recrystallized calcite aggregates resemble those found along the principal slip surface of the Garam thrust, South Korea, exhumed from

Raman probing of competitive laser heating and local recrystallization effect in ZnO nanocrystals

The competitive laser-induced local heating and recrystallization effects in ZnO nanocrystals embedded in a MgO/ZnO stack are reported via resonance Raman spectra. The dependence of the intensity, energy, and resonance effects of the longitudinal optical (LO) phonon on laser excitation condition are discussed in the context of Fröhlich interaction. Redistribution of defects, impurity-diffusion, and grain regrowth caused by thermal and photochemical effects lead to significant changes in coupling strength of electron-phonon interaction, and the resonance behaviors are strongly affected by the interplay of local heating, heat trapping, and local structural modification in such nanostructures.

Northwest Africa 4797: A strongly shocked ultramafic poikilitic shergottite related to compositionally intermediate Martian meteorites

Abstract– Northwest Africa (NWA) 4797 is an ultramafic Martian meteorite composed of olivine (40.3 vol%), pigeonite (22.2%), augite (11.9%), plagioclase (9.1%), vesicles (1.6%), and a shock vein (10.3%). Minor phases include chromite (3.4%), merrillite (0.8%), and magmatic inclusions (0.4%). Olivine and pyroxene compositions range from Fo66–72,En58–74Fs19–28Wo6–15, and En46–60Fs14–22Wo34–40, respectively. The rock is texturally similar to “lherzolitic” shergottites. The oxygen fugacity was QFM−2.9 near the liquidus, increasing to QFM−1.7 as crystallization proceeded. Shock effects in olivine and pyroxene include strong mosaicism, grain boundary melting, local recrystallization, and pervasive fracturing. Shock heating has completely melted and vesiculated igneous plagioclase, which upon cooling has quench‐crystallized plagioclase microlites in glass. A mm‐size shock melt vein transects the rock, containing phosphoran olivine (Fo69–79), pyroxene (En44–51Fs14–18Wo30–42), and chromite in a groundmass of alkali‐rich glass containing iron sulfide spheres. Trace element analysis reveals that (1) REE in plagioclase and the shock melt vein mimics the whole rock pattern; and (2) the reconstructed NWA 4797 whole rock is slightly enriched in LREE relative to other intermediate ultramafic shergottites, attributable to local mobilization of melt by shock. The shock melt vein represents bulk melting of NWA 4797 injected during pressure release. Calculated oxygen fugacity for NWA 4797 indicates that oxygen fugacity is decoupled from incompatible element concentrations. This is attributed to subsolidus re‐equilibration. We propose an alternative nomenclature for “lherzolitic” shergottites that removes genetic connotations. NWA 4797 is classified as an ultramafic poikilitic shergottite with intermediate trace element characteristics.

Geologic Setting, Sedimentary Architecture, and Paragenesis of the Mesoproterozoic Sediment-Hosted Sheep Creek Cu-Co-Ag Deposit, Helena Embayment, Montana

The northern margin of the Helena Embayment contains extensive syngenetic to diagenetic massive pyrite horizons that extend over 25 km along the Volcano Valley-Buttress fault zone and extend up to 8 km basinward (south) within the Mesoproterozoic Newland Formation. The Sheep Creek Cu-Co deposit occurs within a structural block along a bend in the fault system, where replacement-style chalcopyrite mineralization is spatially associated mostly with the two stratigraphically lowest massive pyrite zones. These mineralized pyritic horizons are intercalated with debris flows derived from synsedimentary movement along the Volcano Valley-Buttress fault zone. Cominco American Inc. delineated a geologic resource of 4.5 Mt at 2.5% Cu and 0.1% Co in the upper sulfide zone and 4 Mt at 4% Cu within the lower sulfide zone. More recently, Tintina Resources Inc. has delineated an inferred resource of 8.48 Mt at 2.96% Cu, 0.12% Co, and 16.4 g/t Ag in the upper sulfide zone. The more intact upper sulfide zone displays significant thickness variations along strike thought to represent formation in at least three separate subbasins. The largest accumulation of mineralized sulfide in the upper zone occurs as an N-S–trending body that thickens southward from the generally E trending Volcano Valley Fault and probably occupies a paleograben controlled by normal faults in the hanging wall of the Volcano Valley Fault. Early microcrystalline to framboidal pyrite was accompanied by abundant and local barite deposition in the upper and lower sulfide zones, respectively. The sulfide bodies underwent intense (lower sulfide zone) to localized (upper sulfide zone) recrystallization and overprinting by coarser-grained pyrite and minor marcasite that is intergrown with and replaces dolomite. Silicification and paragenetically late chalcopyrite, along with minor tennantite in the upper sulfide zone, replaces fine-grained pyrite, barite, and carbonate. The restriction of chalcopyrite to inferred synsedimentary E- and northerly trending faults and absence of definitive zonation with respect to the Laramide Volcano Valley Fault in the lower sulfide zone suggest a diagenetic age related to basin development for the Sheep Creek Cu-Co-Ag deposit.

Tailored Heat Treated Accumulative Roll Bonded Aluminum Blanks: Microstructure and Mechanical Behavior

Aluminum alloy AA6016 was accumulative roll bonded up to eight cycles and investigated regarding formability by bending tests. Due to the limited bendability of accumulative roll bonding (ARB) processed materials, a tailored laser heat treatment was performed along the bending edge before forming. This tailored laser heat treatment causes a local recrystallization and recovery of the bending samples at the deformation zone, which locally increases ductility and allows higher bending angles achievable with lower forming forces. Between the recrystallized heat treated zone and the unaffected ultrafine-grained (UFG) base material, a gradient in grain size with a bimodal region is formed. This observed microstructural profile is confirmed by local mechanical testing measuring the hardness and strain rate sensitivity by nanoindentation techniques.

Analysis of abrasive blasting of DOP-26 iridium alloy

The effects of abrasive blasting on the surface geometry and microstructure of DOP-26 iridium alloy (Ir—0.3% W—0.006% Th—0.005% Al) have been investigated. Abrasive blasting has been used to control emissivity of components operating at elevated temperature. The effects of abrasive blasting conditions on surface morphology were investigated experimentally using surface profilometry. A simplified model was used to estimate the effects of process parameters on surface deformation and residual strain distribution. The surface geometry is found to be insensitive to the abrasive blast process conditions of nozzle pressure and standoff distance considered in this study. Modeling results suggest that the angularity of the abrasive particle has an important role in determining surface geometry and residual strains. Abrasive blasting causes localized surface strains and localized recrystallization, but it does not affect grain size following extended exposure at elevated temperature. The dependence of emissivity of the DOP-26 alloy on mean surface slope follows a similar trend to that reported for pure iridium.

Formability of Ultrafine-Grained AA6016 Sheets Processed by Accumulative Roll Bonding

Aluminium alloy AA6016 was accumulative roll bonded up to eight cycles in order to produce an ultrafine-grained microstructure. The formability of these sheets was investigated by means of bending tests. Furthermore the influence of a local laser heat treatment at the bending edge is observed. The strength of the UFG samples is increased by a factor of around two compared to the conventionally grained T4 condition which also results in up to 50 % higher punch forces needed for bending of ARB processed samples. An anisotropic bending behaviour is observed. By applying a tailored laser heat treatment along the bending edge prior to the bending tests a local recrystallization and recovery at the deformation zone of the samples is achieved. Thus, ductility is increased locally whereby bending to an angle of 80° is possible with lower forming forces compared to the non-heat treated specimens. The results are compared to previous studies on mechanical properties and formability investigations of ARB processed AA6016.

Ultrafine Grain Structure Evolution in AA6085 Aluminium Alloy Processed by HPT at Increased Temperature

In this study ultrafine grain structure evolution during high pressure torsion (HPT) of commercial aluminium alloy AA6082 at increased temperature is presented. Two different initial structural states of the alloy were prepared by thermal treatment. The progress in structure refinement in dependence on the shear strain level strain was investigated by TEM of thin foils. The impact of different amount of strain (εef) introduced was analyzed with respect to the effect of increased temperature. The microhardness results measured across the deformed discs pointed out that some data scattering. The results of microstructure analyses showed that ultrafine grain (ufg) structure was already formed in deformed disc upon the first turn, regardless the initial structure of alloy, resulting from prior thermal treatment. The observed heterogeneity in ufg structure formation across the deformed disc was observed, supporting microhardness results scattering. By increasing the strain level (number of turns N-2,4,6), more effectively homogenized ufg structure was observed across the deformed discs. The effect of increased deformation temperature became evident and dynamic recrystalization modified locally ufg structure.. The retardation of new grains growth and higher thermal stability of ufg structure was observed, when two steps thermal treatment of alloy (quenching and ageing) was executed prior deformation. Strength measurements results yielded form tensile tests showed that the effect of structure strengthening was degraded by local recrystallization. The results of torque measurement versus the time showed that the torque required to deform the sample was increasing until the first turn and then kept stable or even decreased.

Effect of Hot-Rolling and Warm-Rolling Process on Properties of Cast-Rolling AZ31B Magnesium Alloy Strip

The effect of different temperature, passes and deformation rates of rolling process on the microstructure and mechanical properties of general cast-rolling magnesium strip and compound energy-field (electromagnetic field and ultrasonic wave) cast-rolling magnesium strip were investigated. The results of microstructure observation showed that the recrystallized temperature in compound energy-field cast-rolling magnesium strip was lower than those of the general cast-rolling magnesium strip. When rolling at 250°C, the recrystallization of general cast-rolling magnesium strip was not remarkable, while the compound energy-field cast-rolling magnesium strip's local recrystallization was observed; while in the case of rolling temperature of 300°C, the general cast-rolling magnesium strip shows local recrystallization and remarkable fibrous structure, while the compound energy-field cast-rolling magnesium strip was fully recrystallized, and the grain became finer and uniform; rolling at 400°C, both general cast-rolling magnesium strip and compound energy-field cast-rolling magnesium strip were fully recrystallized. The results of EDS analysis showed that precipitates of general cast-rolling magnesium strip were numerous and concentrated in and near the grain boundary, while the precipitates of compound energy-field cast-rolling magnesium strip were few and dispersed in the grain boundary in small particles. The results of mechanical properties measurement showed that the σb,σ0.2 and δ of compound energy-field cast-rolling magnesium strip enhanced by 11%, 22.2%, 145% and 13.6%, 19.7%, 127.8%, respectively, compared to general cast-rolling magnesium strip after three rolling passes at the rolling temperature of 250°C and 300°C.

Microstructure of spray-formed FGH4095 after static recrystallization

For the study of solution heat treatment characteristic of spray-formed FGH4095 after near iso thermal forging, the superalloy specimens, which have been hot isostatically pressed (HIPed) and forged with a 75% compression ratio, are solution heat treated at 1120℃, 1140℃ and 1160℃ for 10, 20 and 40 min respectively, and oil quenched. The characteristics of static recrystallization process including grain size and precipitated phase after heat treatment are discussed. The results show that the temperature of solution heattreatment has a great influence on the microstructure. In heat treatment at 1120℃ the recrystallization is slow, and the necklace structure is formed due to the localized incomplete recrystallization; at 1140℃ for 40 min, the static recrystallization is basically completed, the average grain size is about 8 μm; at 1160℃, the recrystallization is finished in 10 min, and the grains grow up to about 18 μm.

Effect of Annealing Process on Microstructure and Properties of Roll-Casting AZ31B Mg Alloy Sheet

The effect of annealing temperature and time on the microstructure and mechanical properties of AZ31B Mg alloy sheets were investigated. The specimens were deformed by general roll-casting and combining energy-field roll-casting (electromagnetic field and ultrasonic). The microstructure analysis showed that the re-crystallization temperature of combining energy-field Mg sheet was lower than that of general Mg sheet. It has been found that at the annealing of 250°C, no obvious re-crystallization occurred for the general Mg strip sheet, while the local re-crystallization occurred for the Mg strip sheet with combining energy-field roll-casting. However, in the condition of annealing at 300°C, the specimens of roll-casting Mg strips fully re-crystallized with the holding time of 4h, and the specimens with compound energy-field Mg strip had fine grains and uniform microstructure, and the average grain diameter were 14∼19μm, 8∼13μm for the general Mg strip sheet and combining energy-field Mg strip sheet, respectively. When the specimens were annealed at 400°C, the grains became coarse within 1h, the average grains diameters were 20∼25μm and 28∼33μm respectively for the general Mg roll-casting sheet and combining energy-field Mg roll-casting sheet when annealing at 400°C for 1h. The results of EDS showed that the precipitates amount of annealed Mg roll-casting sheets were reduced by annealing, the precipitates of general Mg roll-casting sheet with thicker size were enriched on the grain boundaries. The results of the mechanical properties indicated that the plastic deformation of roll-casting Mg sheets was improved significantly; Under the annealing condition of 300°C × 4h, the values of HBS, σb, σ0.2 and δ of combining energy-field Mg strip were improved by 4.7%, 17.2%, 34.1%, 74.6%, compared to general Mg sheet.

Influence of the characteristic of recrystallization grain boundary on the formation of creep cracks in a directionally solidified Ni-base superalloy

Creep tests of a directionally solidified (DS) Ni-base superalloy specimens containing local recrystallization (RX) were carried out at 980 °C/235 MPa and the influence of the characteristic of RX grain boundary on the formation of creep cracks was investigated. The RX grain boundary morphology, misorientation and dislocation pattern at high, low angle and twin boundaries during creep were examined. It was shown that only a few high angle grain boundaries (GBs), but not all of them cracked during creep and even after ruptured. This is associated with the dislocation mobility at GBs or the morphology of GBs. The possibility of crack formation was discussed based on the transmission behavior of dislocations at different GBs.

Localized Recrystallization Induced by Subgrain Rotation in Sn-3.0Ag-0.5Cu Ball Grid Array Solder Interconnects During Thermal Cycling

The evolution of microstructures and grain orientations of a Pb-free solder interconnect during thermal cycling significantly affects its mechanical properties and failure modes. Thus, Sn-3.0Ag-0.5Cu ball grid array assemblies were subjected to thermal cycling to study the thermomechanical responses of the solder interconnects. The orientations and microstructures of the solder interconnects were studied by optical microscopy with cross-polarized light and scanning electron microscopy with an electron backscattered diffraction analysis system. Localized recrystallization behavior was observed in Pb-free solder interconnects during thermal cycling. Closer examination of the very early stage of recrystallization in the same solder interconnect revealed that the subgrains appeared before the formation of the recrystallized grains, and the orientations of the small recrystallized grains separated by high-angle grain boundaries evolved from the initial orientations by subgrain rotation. The localized recrystallization produced fine-grained microstructures during thermal cycling, providing an additional deformation mechanism for the solder interconnects, i.e., grain boundary sliding, which would have been impossible prior to recrystallization. The grain orientation has a strong effect on damage generation and the subsequent failure mode; initiation and propagation of cracks could be facilitated by the intrinsic anisotropic thermomechanical responses of the differently oriented grains, leading to a change in the crack propagation path and corresponding failure mode.

High-grade contact metamorphism in the Reykjanes geothermal system: Implications for fluid-rock interactions at mid-oceanic ridge spreading centers

Granoblastic hornfels identified in cuttings from the Reykjanes seawater-dominated hydrothermal system contains secondary pyroxene, anorthite, and hornblendic amphibole in locally equilibrated assemblages. Granoblastic assemblages containing secondary orthopyroxene, olivine, and, locally, cordierite and spinel occur within groups of cuttings that show dominantly greenschist facies hydrothermal alteration. Granoblastic plagioclase ranges continuously in composition from An54 to An96, in contrast with relict igneous plagioclase that ranges from An42 to An80. Typical hydrothermal clinopyroxene compositions range from Wo49En3Fs48 to Wo53En30Fo17; clinopyroxene from the granoblastic grains is less calcic with an average composition of Wo48En27Fs25. The hornfels is interpreted to form during contact metamorphism in response to dike emplacement, resulting in local recrystallization of previously hydrothermally altered basalts. Temperatures of granoblastic recrystallization estimated from the 2-pyroxene geothermometer range from 927°C to 967°C. Redox estimates based on the 2-oxide oxybarometer range from log fO2 of −13.4 to −15.9. Granoblastic hornfels comprised of clinopyroxene, orthopyroxene, and calcic plagioclase have been described in a number of ancient hydrothermal systems from the conductive boundary layer between the hydrothermal system and the underlying magma source, most notably in Integrated Ocean Drilling Program Hole 1256D, Ocean Drilling Program Hole 504B, and in the Troodos and Oman ophiolites. To our knowledge, this is the first evidence of high-grade contact metamorphism from an active geothermal system and the first description of equilibrated amphibole-absent pyroxene hornfels facies contact metamorphism in any mid-ocean ridge (MOR) hydrothermal system. This contribution describes how these assemblages develop through metamorphic reactions and allows us to predict that higher-temperature assemblages may also be present in MOR systems.

{111} local configurations: The main source of silicon defects during solid phase epitaxial regrowth modeled by lattice kinetic Monte Carlo

A lattice kinetic Monte Carlo model for defect generation during solid phase epitaxial regrowth (SPER) is presented. It assumes two simple causes for defective Si formation: amorphous atoms in local {111} configurations having a probability to become defective and random nucleation and growth creating alternative crystalline seeds. Simulations are compared with experimental results for (001) and (011) Si substrates with different topologies and aligned to ⟨100⟩ and ⟨110⟩ crystalline axes, showing the model accuracy and validating its assumptions. {111} local recrystallization is the main cause for defective Si generation during SPER, by providing the seeds for defects propagated by SPER.

Influence of Severe Plastic Deformation on Microstructure and Thermal Properties of Cu

The evaluation of microstructure and the thermal diffusivity of copper subjected to severe plastic deformation using multi-axial compression was investigated. The investigations were performed on copper (M1E grade) processed to effective strain at range f =1-14.9. The multi- axial compression resulted in an refining structure. The evolution of dislocation structure, misorientation distribution, crystalline size were observed by using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) equipment with electron back scattered diffraction (EBSD) facility. The thermal diffusivity measurements were performed by using the LFA427 apparatus based on the laser-flash method. Subgrain and grain size for f =3.7 reaches about 250 nm and 550 nm respectively. The local recrystallization occur in analyzed microarea especially at f =7.5 and delay the reduction of sub(grain) size. In consequence no more large changes in structure occur during further processing up to the largest strain. The microstructural phenomena have an influence on the thermal parameters. The value of this parameters insignificantly decreased with increasing of accumulated strain.

Intermediate temperature creep of directionally solidified Ni-based superalloy containing local recrystallization

Intermediate temperature creep of directionally solidified Ni-based superalloys containing local recrystallization (RX) was studied. A sharp reduction of the creep rupture life was observed with increasing the transverse RX area fraction on the cross section of the specimen. Creep curves of specimens containing local RX showed that the steady state creep stage was much shorter than that of the “good” specimens. The creep rates were also slightly higher when there was local RX. The creep and failure mechanism was discussed based on the dislocation morphology in the vicinity of the RX grain boundaries and the formation and propagation of cracks in the RX region according to the microstructure observation of the interrupted creep specimens.

Ultrafine Structure Formation in Aluminium Alloy Processed by HPT and the Mechanical Properties Response

In this study ultrafine grain structure evolution during high pressure torsion (HPT) of commercial aluminium alloy AA6082 at increased temperature is presented. Two different initial structural states of the alloy were prepared by thermal treatment. The progress in structure refinement in dependence on the shear strain level strain was investigated by TEM of thin foils. The impact of different amount of strain (εef) introduced was analyzed with respect to the effect of increased temperature. The microhardness results measured across the deformed discs pointed out that some data scattering. The results of microstructure analyses showed that ultrafine grain (ufg) structure was already formed in deformed disc upon the first turn, regardless the initial structure of alloy, resulting from prior thermal treatment. The observed heterogeneity in ufg structure formation across the deformed disc was observed, supporting microhardness results scattering. By increasing the strain level (number of turns N -2,4,6), more effectively homogenized ufg structure was observed across the deformed discs. The effect of increased deformation temperature became evident and dynamic recrystalization modified locally ufg structure. The retardation of new grains growth and higher thermal stability of ufg structure was observed, when two steps thermal treatment of alloy (quenching and ageing) was executed prior deformation. Strength measurements results yielded from tensile tests showed that the effect of structure strengthening was degraded by local recrystallization. The results of torque measurement versus the time showed that the torque required to deform the sample was increasing until the first turn and then kept stable or even decreased.