Dominant Creep Mechanism Research Articles

Role of threshold stress in creep of IN740H, a γ′-lean Ni-based superalloy

IN740H, a Ni-based superalloy comprising a low-volume fraction of γ′, is a candidate material to be used over long periods at high temperatures and stresses, as conditions prevalent in advanced ultra-supercritical (AUSC) power plants. In this study, IN740H has been tested at temperatures above 700 °C to gain mechanistic insights into its high-temperature creep behavior. The material showed classic signatures of the presence of threshold stress, marked by observation of a high apparent creep stress exponent, n, (e.g., 10 at 750 °C) and a high apparent activation energy for creep, Qc (e.g., ∼545 kJ/mol), along with a rapid increase in n at lower stresses. Accounting for the threshold stress led to a decrease in the values of n and Qc to 4 and 280 kJ/mol, respectively. Furthermore, the transmission electron microscopy and atomic scale compositional analysis reveal the pinning of dislocations at γ-γ′ interface and segregation of Co, Cr and Mo atoms in the regions of γ-γ′ interface rich in dislocations. The above combination of n and Qc and the observation of dislocation pinning at the γ-γ′ interface indicate the dislocation climb over γ′ as the dominant creep mechanism in this γ′-lean Ni-based superalloy, with the detachment of dislocations from the γ-γ′ interface, augmented by the segregation of Co, Cr and Mo, as the mechanism responsible for the realization of the threshold stress. This work, thus, provides a new impetus to research on the long-term structural integrity of γ′-lean Ni-based superalloys exposed to extreme service conditions.

Identifying the activated slip modes and twin variants in compressive creep deformation of Mg-8.0Al-1.0Nd-1.0Gd

The compressive creep deformation mechanism of as-cast Mg-8.0Al-1.0Nd-1.0Gd alloy at 180 °C under constant stress of 60 MPa and 90 MPa was novelly analyzed through the distribution characteristics of in-grain misorientation axes (IGMA). Activated slip modes in the creep process was accurately identified and the structure of dislocations is revealed by the weak beam dark-field (WBDF) technology. The intensities of IGMA are concentrated on 011̅0 and 1̅21̅0 axis demonstrates that 0001112̅0(basal slip) and 112̅2112̅3̅ (pyramidal slip) dominate the deformation mechanism. Tensile twins 101̅21̅011 were extensively activated in compression-creep process and the 101̅21̅011 variants with a twinning trace angle close to 90 deg are 1̅012101̅1 and 101̅21̅011 with para-position. The creep mechanism of the alloy crept at 180°C/60 MPa is dominated by grain boundary sliding triggered by the precipitation of β-Mg17Al12, and pipe diffusion-controlled boundary sliding is the dominant creep mechanism of the alloy under 180 °C/90 MPa. In addition, the results reveal that tensile twins induced by dislocation slip contribute to coordinate the grain c-axis deformation, release the stress concentration caused by dislocation accumulation at the grain boundary.

Metallurgical and Mechanical Properties of Friction Stir-Welded Pure Titanium

Commercially pure titanium (CP-Ti) plates were friction stir welded (FSWed) using a welding tool with a tungsten carbide (WC) pin. The bead-on-plate technique was applied to reduce the effects of welding defects, such as incomplete penetration. Whereas many papers have reported on creep studies of CP-Ti as well as on FSW of CP-Ti, no paper has investigated the creep behavior of a CP-Ti FSW’ed joint. Consequently, the current study focuses on this topic. The current paper, which is part of a broader research project, focuses on the metallurgical processes occurring during the creep of a FSW’ed CP-Ti joint at the temperature range of 550-650 °C. Based on the current study and previous results obtained by the authors, it can be concluded that the weld is not the weakest link. In every case, necking and creep fracture occurred in the parent material (PM), rather than either the thermomechanically affected zone (TMAZ) or the stir zone (SZ), indicating that both zones are more creep-resistant than the parent material. Fractography showed that the fracture surface was typical of creep fracture and that the fracture mechanism was microvoid coalescence and also ruled out any preexisting defect. TEM study of broken crept specimens revealed randomly distributed dislocations but no evidence of grain refinement, hence leading to the conclusion that dislocation glide was the dominant creep mechanism. The technological implication of the current study is that the welding process is safe for use as far as its creep properties are concerned.

Exploring the dependence of creep behavior on the grain size of a peak-aged Mg-10.5Y alloy

In this work, the effects of grain size on the compressive creep behavior of a peak-aged Mg-10.5 wt%Y alloy were studied. Compressive creep tests were conducted at 523 K using three group samples, each having an average grain size of d = 25 µm, d = 50 µm and d = 90 µm along the rolling direction. An inverse Hall-Petch relationship for mechanical strength could be used to evaluate the dependence of creep behavior on the grain size, and the creep resistance was continuously deteriorated with decreasing grain size. The dominant creep mechanisms were pyramidal <c+a> slip, cross-slip and prismatic slip in the d = 25 µm sample whilst pyramidal <c+a> slip, cross-slip and basal slip controlled the creep process in both the d = 50 µm and d = 90 µm samples. In addition, precipitate-free zones (PFZs) decorated randomly the grain boundaries during creep. Both the PFZs width and PFZs amounts were increased as the average grain size decreased, and the softening effects from the frequent activated prismatic slip and profuse PFZs induced the worst creep resistance in the d = 25 µm sample. Thus, the creep resistance of the fine-grained samples was always unsatisfactory even though grain boundary sliding was absent at creep duration. It hopes that this work can enrich the understanding of creep theories and offer important reference to the microstructure design of heat-resistant Mg-RE alloys.

Ligament rotation-dominated creep in stochastic bicontinuous nanoporous metallic glass

Bicontinuous nanoporous metallic glasses (BNPMGs) are promising candidates in functional applications such as energy storage, sensors, and fuel cells. The time-dependent deformation strongly affects their long-term in-service performance. This study investigates the tensile creep behavior and its underlying deformation mechanisms of Cu50Zr50 BNPMGs through molecular dynamics simulations. The creep-recovery fatigue behavior is revealed. Our results manifest that both the transient and steady creep strengths increase with the solid fraction. The transient strength is larger for smaller ligament sizes, but the steady creep strength has very mild sensitivity to the ligament size. The generalized Kelvin model, consisting of two Kelvin units and one Maxwell unit connected in series, can accurately predict the creep and recovery curves. The rotation of individual ligaments, rather than atomic diffusion, is the dominant creep mechanism. During creep, the shear transformation zones are mainly developed on the ligament surface, and the strain in the ligament core is relatively smaller. The creep stress exponent has no definite relation with the creep mechanism and decreases with the increasing solid fraction. With the increase in the creep-recovery cycle number, the creep rate decreases, and the recovery procedure makes a milder impact on the creep response.

On the creep mechanisms and macroscopic creep rate modeling of high-uranium-density composite fuels

UN-U3Si2 composite fuel is a promising candidate of Accident Tolerant Fuels (ATFs). Its in-pile creep performance will have an important impact on the irradiation-induced thermo-mechanical coupling behavior and safety of fuel elements. Based on the existing mechanism-based creep models of UN and U3Si2, the finite element analysis was performed for the multi-scale creep behaviors of various UN-U3Si2 composite fuels, and the influences of the U3Si2 volume fraction, applied stress, temperature, fission rate, and grain size were investigated. The dominant creep mechanisms under different conditions were proposed, and the mechanism-based macroscopic creep rate model for the UN-U3Si2 composite fuels were correspondingly developed, quantitatively correlating with the macroscopic creep rate with the U3Si2 vol fraction, temperature, fission rate and equivalent stress. The creep rate predictions obtained by this model were in good agreement with the results of the finite element simulation. The research results indicate that: (1) the irradiation or thermal diffusion creep contributions from the UN and U3Si2 phases were dominated under various conditions; (2) the dislocation creep contributions from the dispersed-phase of U3Si2 were appreciable at the temperatures ranged from 500 K to 1300 K, while those of the matrix-phase of UN appeared only at an extremely high temperature of 1300 K; (3) different from the ordinary inert-matrix dispersion fuels, the macroscopic creep rates of UN-U3Si2 composite fuels were predicted to be almost independent of burnup, due to the slight difference in the irradiation swelling of UN and U3Si2; (4) the total creep contribution proportions of the U3Si2 or UN phase were almost equal to the initial volume fractions, while the creep contribution ratios within the UN or U3Si2 phase vary under different conditions. The evolutions of various creep contributions with the fission density were attributed to the fuel-swelling induced additional stresses.

Compressive creep behavior and microstructural evolution of sand-cast and peak-aged Mg–12Gd–0.4Zr alloy at 250 °C

Magnesium (Mg) alloys with high concentrations of Gd additions are known to exhibit high strength and good creep resistance at elevated temperatures. However, the main mechanisms including microstructural evolution and dislocation configurations for clarifying the low creep rates of Mg–Gd–Zr alloys are still controversial. The present work investigates the compressive creep behavior of both the sand-cast and peak-aged Mg–12Gd–0.4Zr (wt.%) alloys at a fixed temperature of 250 °C under the applied stress range of 60–100 and 80–120 MPa, respectively. It is revealed that β' and β'F precipitates distribute alternately forming precipitate chains in Mg–Gd–Zr alloys. Furthermore, β'+β'F precipitate chains led to the honeycomb-like structure in the sand-cast alloy during the creep process, improving its creep resistance to some extent. Nevertheless, weakly strengthening β1 precipitates occurred and detrimental β phases coarsened, which weakened the creep performance of the sand-cast alloy. However, the slight improvement of creep resistance in the peak-aged Mg–12Gd–0.4Zr alloy can be mainly attributed to the formation of precipitate-free zones (PFZs) and also the premature coarsening of β'+β'F precipitate chains. During creep, the cross slip of basal and prismatic <a> dislocations become the dominant creep mechanism for the sand-cast alloys. By contrast, the cross-slip of basal <a> dislocations and pyramidal <c + a> dislocations is the dominant creep mechanism for the peak-aged alloys, which was arrested by precipitates then strengthening the creep resistance of peak-aged alloys.

Creep Behavior of Ti–6Al–4Nb–4Zr Fabricated by Powder Bed Fusion Using a Laser Beam

Powder bed fusion using a laser beam (PBF-LB) was performed for Ti-6Al-4Nb-4Zr (wt%) developed by our group to improve the oxidation resistance at temperatures greater than 600 °C by adding Nb and Zr to near-α alloys. Microstructure evolution of the PBF-LB samples by heat treatment was investigated, especially for heat treatment duration in the α + β phase, cooling rate, and heat treatment in the β phase. The equiaxed α phase formed during heat treatment along the melting-pool boundaries. The high volume fraction of the α phase and high Nb contents in the β phase was obtained by slow cooling (furnace cooling) compared with fast cooling (air cooling). The α/β lamellar structure formed in the melting pool boundaries with 100 μm in size and no equiaxed α phase formed along the boundaries by heat treatment in the β phase regime. Creep life at 600 °C and 137 MPa was similar for the air-cooled and furnace- cooled samples, but the slightly slower deformation was obtained in the furnace-cooled sample. Creep life of the sample in the β phase region drastically increased due to the absence of the equiaxed α phase. Dominant deformation mechanism of creep was grain boundary sliding. The small equiaxed α phase accelerated grain boundary sliding.

Size- and temperature-dependent mechanical properties of metallic lithium

Lithium (Li) metal anodes are under active investigation to boost the energy density of rechargeable lithium-ion batteries (LIBs). In developing such anodes, uncontrolled Li plating/stripping remains a critical issue, which calls for a deep understanding of the deformation characteristics of Li. Here we report an experimental study on the elastic, plastic, and creep behavior of metallic Li over a wide range of temperatures and length scales that are relevant to battery applications. We characterized these mechanical properties via environmentally controlled, variable-temperature nanoindentation. A strong size effect on the indentation hardness of Li was observed and rationalized by a modified Nix–Gao model incorporating the effect of surface energy. Size- and temperature-dependent creep behavior of Li was also analyzed and attributed to self-diffusion-controlled dislocation climb as the dominant creep mechanism.

Comparative Study of Creep and Stress Relaxation Behaviour during Ageing of 7050 Aluminum Alloy

This work focuses on quantitatively investigating the relationship between creep and stress relaxation of 7050 aluminum alloy at ageing temperatures. The creep strain rates, creep exponent, n, and activation energy were extracted from both the creep and stress relaxation curves to explore the creep mechanisms. Results showed that higher applied stress promotes the creep and stress relaxation extents. The calculated creep strain rates from creep and stress relaxation curves located in similar ranges and share similar n values (n = 3.7 for creep and n = 3.5 for stress relaxation), indicating that both tests are dominated by the dislocation slip mechanism. Additionally, the n value for creep tests is a constant throughout the tests, indicating that the dominant creep mechanism is unchanged. However, the activation energy changes from 123 kJ/mol to 139 kJ/mol, possibly due to evolved dislocations. Such a new finding could provide a supporting mechanism for building constitutive equations depending on the evolved A value. Furthermore, compared to the single-stage creep ageing, no primary creep was observed in T74 multi-stage creep ageing while similar amount of total creep strains was achieved. This suggests an alternative loading sequence for creep age forming of 7050 aluminum alloy, i.e., loading at the second stage to avoid prolonged exposure to high temperatures, extend the tool life, and achieve similar amounts of inelastic deformations. Based on all the above studies, creep and stress relaxation have a certain relationship. This paper provides a theoretical basis for future research on creep ageing forming of 7050 aluminum alloy.

The microstructure evolution and phase transformation behavior of a β-solidifying γ-TiAl alloy during creep

The microstructural evolution and creep behavior of the Ti-43.5Al–4Nb–1Mo-0.1B alloy have been investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM). The excellent creep property was obtained with a fully lamellar (FL) microstructure containing the least grain boundary βo phase (GB-βo). TEM results revealed that after creep testing the α2 →βo phase transformation was observed in the FL microstructure. The formation βo phase is associated with the accumulation of Mo element, which is confirmed by the energy-dispersive X-ray spectroscopy (EDS). Moreover, the formation of βo precipitation in α2 lamellae effectively decreased the generation of dislocations in (α2/γ) lamellae, thereby improving the creep resistance. For the near gamma (NG) microstructure of the as-forged sample, a large number of dislocations and dislocation tangles were observed in the globular γ phase (γ-glob), which are considered to be the dominant creep mechanism. Moreover, the ellipsoidal ωo phase was observed in the GB-βo phase, accompanying with dislocations and sub-boundaries formation. In sum, the excellent creep property of the β-solidifying γ-TiAl alloy is attributed to the fine FL structure with a small amount of GB-βo phase and the formation of βo precipitation in (α2/γ) lamellae.

Hypo-eutectic microstructure formation and nanomechanical response in Sn-3.0Ag-0.5Cu solder balls: Effects of undercooling

The microstructure control and refinement in length scale are pursued in the development of next generations of Pb-free solder alloys with high reliability in harsh environments. In the present work, the influences of nucleation undercooling, as brought by solder ball size, over the microstructure evolution and nanomechanical behavior in Sn-3.0Ag-0.5Cu (wt%) Pb-free solder alloys, have been quantitively investigated using Differential Scanning Calorimeter (DSC), Scanning Electron Microscopy (SEM) and nanoindentation. The results reveal that undercooling increases with the decrease of solder ball size. The frequency of interlaced grain microstructure was significantly increased in 200 μm balls, with a further increase of undercooling by ~10 K. The volume fraction of primary β-Sn increased with larger undercooling, leading to microstructure refinement with a finer spacing of both β-Sn dendrite and eutectic Ag3Sn. The length scale of refinement is on the order of ~2, as the solder ball size reduced from 650 μm to 200 μm. Nano-hardness and creep resistance increase with smaller ball size and larger undercooling. Nano-hardness values are relatively higher as more eutectic regions being measured due to the strengthening effect of finer and denser eutectic Ag3Sn, and also the refinement of interlaced β-Sn grains. The creep exponent is insensitive to the loading force or solder ball size. The variation of nanomechanical deformation behavior was reduced in the 200 μm balls, due to the substantial microstructure refinement, while the dominant creep mechanism stays as the dislocation climb for various solder ball sizes.

Microstructural Effects on Irradiation Creep of Reactor Core Materials

The processes that control irradiation creep are dependent on the temperature and the rate of production of freely migrating point defects, affecting both the microstructure and the mechanisms of mass transport. Because of the experimental difficulties in studying irradiation creep, many different hypothetical models have been developed that either favour a dislocation slip or a mass transport mechanism. Irradiation creep mechanisms and models that are dependent on the microstructure, which are either fully or partially mechanistic in nature, are described and discussed in terms of their ability to account for the in-reactor creep behaviour of various nuclear reactor core materials. A rate theory model for creep of Zr-2.5Nb pressure tubing in CANDU reactors incorporating the as-fabricated microstructure has been developed that gives good agreement with measurements for tubes manufactured by different fabrication routes having very different microstructures. One can therefore conclude that for Zr-alloys at temperatures < 300 °C and stresses < 150 MPa, diffusional mass transport is the dominant creep mechanism. The most important microstructural parameter controlling irradiation creep for these conditions is the grain structure. Austenitic alloys follow similar microstructural dependencies as Zr-alloys, but up to higher temperature and stress ranges. The exception is that dislocation slip is dominant in austenitic alloys at temperatures < 100 °C because there are few barriers to dislocation slip at these low temperatures, which is linked to the enhanced recombination of irradiation-induced point defects.

Anisotropy and variability in thermal creep behaviour of Zr-2.5Nb pressure tube

The Zr-2.5Nb alloy pressure tubes of Indian Pressurized Heavy Water Reactors were manufactured from double melted ingots initially and subsequently from quadruple melted ingots to reduce impurities such as chlorine, phosphorus and carbon. In the current investigation, creep tests were carried out in the stress range of 0.7–0.9 times the yield strength and the temperature range of 350 °C–450 °C to characterize the thermal creep behaviour of Zr-2.5Nb alloy pressure tubes fabricated from double and quadruple melted ingots. The rupture time, minimum creep rate, stress exponent, activation energy and threshold stresses were obtained by carrying out the creep tests of the samples fabricated with their axis parallel to the axial and transverse directions of the pressure tubes. Experimental analysis revealed that the rupture time for double melted tube was 2–3 times lower than that of quadruple melted tubes, whereas no significant change in minimum creep rate was observed. Stress exponent values were obtained in the range of 3–5 signifying dislocation creep as the dominant creep mechanism. To predict the long-term creep properties, the master curves employing the Larson-Miller and Monkman-Grant methods were also evaluated. The effect of microstructural anisotropy, alloying elements and impurities on the thermal creep behaviour of Zr-2.5Nb pressure tube has been investigated.

Effects of pre-compression on formation of dynamic precipitates and creep anisotropy of hot-extruded AZ91—2Y magnesium alloy

The creep anisotropy behavior under different stresses at 180 °C of hot-extruded AZ91—2Y magnesium alloy with pre-compression (PC) and without pre-compression (NPC) was studied. Microstructure, texture and mechanical properties of the alloy were examined by scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and tensile creep tests. The results revealed that the creep resistance was proportional to the volume fraction of spherical Mg17Al12 precipitates. The dynamic precipitation of large volume fraction of lamellar Mg17Al12 in NPC samples leads to the basal 〈a〈 slip as the dominant creep mechanism, and the NPC samples have obvious anisotropy. In the PC samples, dynamic precipitation of large volume fraction of spherical Mg17Al12 has inhibitory effect on the basal 〈a〉 slip. The pyramidal 〈c+a〉 slip and twinning improve the creep anisotropy resistance significantly.

Effect of microstructure inhomogeneity on creep behavior of friction stir welding 7B50-T7451 aluminum alloy thick plate joint

Microstructure inhomogeneity and through-thickness creep properties of friction stir welding (FSW) 7B50-T7451 aluminum alloy thick plate joint were investigated. The results show that creep properties of the FSW joint deteriorate along the thickness direction from the top to the bottom. Both the grain size and fraction of the low-angle grain boundaries (LAGBs) in the weld nugget zone (WNZ) decrease from the top to bottom. A larger volume of precipitate free zone (PFZ) and coarser precipitates in the bottom slice reduce creep resistance compared with the top. The precipitates in the heat-affected zone (HAZ) exhibit continuous coarsening with the increase of creep temperature, inducing the decrease of threshold stress. The dominant creep mechanism transforms from dislocation creep in the HAZ to grain boundary sliding (GBS) in the WNZ when creep temperature increases. The fracture mode also changes from transgranular to intergranular fracture.

Micro mechanical property investigations of Ni-based high-temperature alloy GH4169 based on nanoindentation and CPFE simulation

In this research, the microscopic deformation behavior of GH4169 superalloy is investigated by a series of nanoindentation experiments and simulations based on crystal plasticity finite element (CPFE) model, including hardness, creep displacement and stress distribution around indentation. In this regard, the crystal plasticity constitutive model based on dislocation slip for face-centered cubic (FCC) crystal of concern is summarized and numerically implemented at first. Moreover, nanoindentation experiments are performed on specimens with various peak loads and load times to investigate the mechanical response and deformation mechanism at the micro-scale. Nanoindentation test results show that load rate, peak load, and nanoindentation size effect (ISE) all affect the microscopic deformation behavior of GH4169. The value of creep stress exponent, m, calculated from the creep experimental data is greater than 3, indicating that dislocation slip is dominant creep mechanism at room temperature.The nanoindentation simulation data based on the crystal elastic–plastic parameters determined by the trial-and-error method are in good agreement with the experimental data, demonstrating that the CPFE simulation results are credible. Therefore, this study can be used as a reference to investigate other alloy materials.

Microstructural Evolution during Accelerated Tensile Creep Test of ZK60/SiCp Composite after KoBo Extrusion.

In the current study, the creep properties of magnesium alloy reinforced with SiC particles were investigated. For this purpose, ZK60/SiCp composite was produced by the stir casting method following the KoBo extrusion and precipitation hardening processes. The creep tests were performed at 150 °C under 10–110 MPa. The results showed that the stress exponent (n) and the average true activation energy (Q) was changed at high stresses, was found with increasing stress, the creep mechanism changing from grain boundary sliding to dislocation climb. The results of microstructure characterization after the creep test showed that at low stresses, the dynamic recrystallization resulting from twinning induced the GBS mechanism. However, at high stresses, with increasing diffusion rates, conditions are provided for dynamic precipitation and the dislocation climb of the dominant creep mechanism. Examination of the fracture surfaces and the surrounding areas showed that the cavity nucleation in the ternary boundary and surrounding precipitation was the main cause of damage. The evaluation of the samples texture after creep showed that the unreinforced alloy showed a moderately strong fiber texture along the angle of ϕ1 = 0–90°, which was tilted about Φ = 10°. A new strong texture component was observed at (90°, 5°, 0°) for the composite sample, which crept due to minor splitting of the basal pole by ~5° toward RD.

Nanoindentation creep behavior of diverse microstructures in a pre-strained interstitial high-entropy alloy by high-throughput mapping

Time-dependent plastic deformation, also known as creep, can occur in high-melting-point materials at room temperature when subjected to submicron plastic contact (e.g., components in micro-electronic mechanical systems) due to the extremely high stress conditions. Previous investigations of creep behavior at submicron scale mainly focus on uniform microstructures, whereas recently developed high-performance structural materials usually show complex microstructural heterogeneities. Here, we demonstrate a high-throughput nanoindentation approach to unveil the creep behavior of locally diverse microstructures, via a case study on an interstitial high-entropy alloy (iHEA). The prototype iHEA specimen was firstly pre-strained by severe cold-rolling to achieve diverse microstructure features including dense dislocations, nanotwins and nanograins. Nanoindentation mapping with 144 indents is conducted to collect creep data from all types of diverse microstructures, followed by systematical calculations based on power-law analysis. Then intuitive contour maps of nanohardness (H), strain rate (ε˙) and stress exponent (n) are attained. The individual creep mechanism of each microstructure variant is evaluated by correlating local microstructure features with corresponding creep responses from these contour maps. With the increase of n value for different sample regions, the ε˙ value inversely reduces and the corresponding dominant creep mechanism gradually converts from diffusion-mediated mode to dislocation-controlled one. The presence of nanograins and nanotwins significantly hinders dislocation interactions and promotes stress-induced diffusion. This work verifies that nanoindentation creep behavior is highly correlated with local microstructure features, and the mapping approach is feasible for evaluating creep-resistance of locally diverse microstructures under extremely high-stress conditions.

Microstructure and nanoindentation creep behavior of TiC reinforced steel matrix composite after stabilizing heat treatments

The microstructure and nanoindentation creep behavior of characteristic phases in TiC reinforced steel matrix composite after stabilizing heat treatments were investigated. The results showed that the microhardness of matrix increased from 4.85 ± 0.30 GPa in the annealed sample to 13.45 ± 0.71∼ 16.06 ± 0.88 GPa after stabilizing heat treatments, and the apparent hardness of TiC particle was also improved due to the martensitic strengthening of matrix. The dominant creep mechanism of the composite was dislocation movement, the primary micro creep stage dominated the micro creep behavior of annealed composite and the steady state creep dominated the micro creep behavior of stabilized composites. The micromechanical properties of the characteristic phases in the composite after TCC treatment were well matched, and the overall creep resistance of that was excellent, which provided theoretical support in achieving the consistency of micromechanical properties of the composite during the stabilizing heat treatments.