Specific Orientation Relationship Research Articles

Van der Waals semiconductor InSe plastifies by martensitic transformation.

Inorganic semiconductor materials are crucial for modern technologies, but their brittleness and limited processability hinder the development of flexible, wearable, and miniaturized electronics. The recent discovery of room-temperature plasticity in some inorganic semiconductors offers a promising solution, but the deformation mechanisms remain controversial. Here, we investigate the deformation of indium selenide, a two-dimensional van der Waals semiconductor with substantial plasticity. By developing a machine-learned deep potential, we perform atomistic simulations that capture the deformation features of hexagonal indium selenide upon out-of-plane compression. Unexpectedly, we find that indium selenide plastifies through a martensitic transformation; that is, the layered hexagonal structure is converted to a tetragonal lattice with specific orientation relationship. This observation is corroborated by high-resolution experimental observations and theory. It suggests a change of paradigm, where the design of new plastically deformable inorganic semiconductors can focus on compositions and structures that facilitate phase transformations, going beyond the conventional dislocation slip.

On the formation of oxide inclusions in the high nitrogen chromium-manganese steel produced by the Wire and Arc Additive Manufacturing

Oxide inclusions significantly impeded the mechanical properties of the Wire and Arc Additive Manufacturing (WAAM) made high nitrogen Cr–Mn austenite stainless steels (HNSs). This paper focused on the inclusions' component, crystallization characteristics and formation mechanism. Results revealed that there are two types of inclusions: the round-shape nano-size inclusion (Type-I) and the micron-size island-shape inclusion (Type-II). The Type-I inclusion usually consists of the MnO particle or the combination of the MnO, Si-oxides and precipitations (MnS or Cr2N). Most of the Type-I oxide inclusion is located in the range between 300 nm and 700 nm,the number of Type-I oxide inclusion takes the main part of 69.7%.With higher content, smaller size and more even distributions, the isolated Type-I oxide inclusions would be beneficial to the mechanical properties owing to the Orowan strengthening mechanism. The Type-II inclusion is mostly composed of the MnO matrix and the coherent chromite spinel (MnCr2O4). In general, the larger the size, the more serious the negative impact on mechanical properties. And there was a strong negative correlation between the size and quantity of type II oxide inclusions. After heat treatment, abundant phase transformations occurred in the Type-II inclusions and some harmful phases (Sigma, MnS et cl.) were often found in or around the inclusions with specific orientation relationships. During deposition, the unstable droplet transformation and the trapped residual slag were the main causes for the inclusions in the molten pool.

Equiatomic CoCrFeNi Thin Films on C‐Sapphire: The Role of Twins and Orientation Relationships

Face‐centered cubic (fcc) metals deposited onto crystalline substrates grow heteroepitaxially with specific orientation relationships (ORs). The ORs depend on a number of factors including lattice mismatch, bonding and the relative symmetry between the surface and the film. Less explored factors include defects like growth and annealing twins. In this study, a high density of nanotwins in as‐deposited films delay grain growth of OR1 (, ) grains up to 0.56 Tm. A new OR with respect to the c‐sapphire substrate is found, compared to the well‐known OR1 and OR2 which grow with the . This is named OR3, grows above 0.56 Tm with . The OR3 growth is related to strain and defect energy advantage. An unusual OR accompanies OR3 in most films, occupying an area fraction of >0.3. A minute (<0.05) but consistent fractions of , , , and all parallel to and related to annealing twins in exact and near and grains are observed. The study opens new directions in the crystallography of ORs, considering the role of twins in addition to the surface and strain energies.

Nanocarbon architecture-intervened interface design of Cu matrix composites towards necking-delayed fracture and toughening

In-situ formed interfacial carbides always sacrifice the structure integrity of reinforcement in nanocarbon/metal composites. Herein, leaf-like carbon nanotube-graphene nanoribbon (CNT-GNR) hybrids, consisting of CNT midrib and GNR margin, was synthetized to solve the above dilemma in nanocarbon-CuCr system. Results demonstrate that high-density nano-sized Cr7C3, which had specific orientation relationship related to the CuCr matrix ([0 0 1]Cr7C3//[011]CuCr, (2‾ 20) Cr7C3//(11 1‾)CuCr), was in-situ formed at GNR-Cu interface via “heterogeneous nucleation-growth” pattern. Meanwhile, the integrity of CNT midrib was well-retained. In-situ SEM tensile results show that such designed interface effectively prevents crack propagation, makes crack blunt via coordinated plastic deformation of local matrix, and guarantees the failure of CNT-GNR by breakage mode, being crucial for exerting the toughening and promoting strength-ductility synergy of CNT-GNR/CuCr.

Phase formation and elemental transport in the vacuum diffusion bonding between CoCrFe0.2NiMn and CoCrFe16NiMn multicomponent alloys

To efficiently explore the influence of Fe content on the phase stability of the multicomponent CoCrFexNiMn (hereafter abbreviated as Fex) alloys. A diffusion layer with continuous, concentration gradient of Fe element is created based on diffusion couple technique. The microstructure and element distribution of the diffusion bonded layer between Fe0.2 and Fe16 alloys are analyzed. A new layer of FCC and HCP solid solution phases generates in the diffusion zone, which is consistent with the prediction of parametric approach and phase diagram calculation. As diffusion proceeds, the FCC phase is transformed from the BCC phase with the decreasing of Fe content and the HCP phase might be the transitional phase during this transition. The newly formed FCC and HCP phases are shown specific orientation relationships with the BCC phase. Elemental analysis indicated that the diffusion rate of the alloy components in the FCC phase is Cr > Mn > Co > Ni. The large concentration gradient in the diffuse interface and grain boundaries diffusion of BCC phase promoted the Fe diffusion, causing the BCC phase to transform into FCC phase.

Novel Ti3SiC2-(Ti, Zr)B2 toughened (Ti, Zr)C-based composites with enhanced mechanical properties fabricated by dual in situ reactions hot-pressing at low temperature

The fully dense Ti3SiC2-(Ti, Zr)B2 toughened (Ti, Zr)C-based composites were fabricated at 1400–1600 °C for the first time by dual in situ reactions hot-pressing with TiC, ZrB2, and Si as the initial powders. The influence of ZrB2, Si content and sintering temperature on the microstructure and mechanical properties of the composite was reported. When 10 mol% ZrB2 was added, Si combined with residual TiC to form Ti3SiC2 and SiC. However, with the addition of ZrB2 increase to 20 mol% and 30 mol%, Si participated in the formation of ZrSi and was not enough to react with TiC to form Ti3SiC2. The low-temperature in situ reactions, multiphase coupling effects, and the pinning effect of nano-SiC refine the microstructure of the composites. There are specific crystal orientation relationships between (Zr, Ti)C and (Ti, Zr)B2, as well as between (Ti, Zr)C and SiC. The layered Ti3SiC2 and plate-like (Ti, Zr)B2 by dual in situ reactions effectively improve the fracture toughness of the composites. The 10 ZB-15 possesses a highest fracture toughness of 6.1 MPa⋅m1/2. The 30 ZB-16 has the good comprehensive mechanical properties. The fracture toughness, flexural strength, and hardness of 30 ZB-16 is 5.6 MPa⋅m1/2, 679 MPa, and 26.4 GPa, respectively. The Ti3SiC2 and TiB2 formed during dual in situ reactions enables the composite to exhibit excellent oxidation resistance and wear resistance.

Experimental and ab initio derivation of interface stress in nanomultilayered coatings: Application to immiscible Cu/W system with variable in-plane stress

Interface stress is a fundamental descriptor for interphase boundaries and is defined in strict relation to the interface energy. In nanomultilayers with their intrinsically high interface density, the functional properties are dictated by the interface structure, which is governed by the delicate interaction of residual interface and volume stresses. In the present work, experimental estimations of the interface stress in Cu/W NMLs were compared with corresponding theoretical values as calculated using DFT (adopting an incoherent bcc W{110}/fcc Cu{111} interface with variable in-plane strain). The Cu/W interface stress was experimentally tuned monotonically from positive to negative values by changing the residual stress in the W nanolayers. Qualitative agreement between experiment and simulation was achieved, confirming a decrease of the interface stress from the compressive to the tensile regime. The DFT simulations showed that Cu atoms at the strained Cu/W interfaces are displaced along the in-plane and out-of-plane directions in response to the interface stress. Using a preliminary neural network potential for the Cu–W system, specific in-plane crystallographic orientation relationships for the Cu/W interfaces were also tested, which improved quantitative agreement between experiment and theory. Assumptions and limitations in experiments and theory for deriving the interface stress are critically discussed.

Effect of trace oxygen on plasma nitriding of titanium foil

Titanium nitride films are prepared by plasma enhanced chemical vapor deposition method on titanium foil using N2 as precursor. In order to evaluate the effect of oxygen on the growth of titanium nitride films, a small amount of O2 is introduced into the preparation process. The study indicates that trace O2 addition into the reaction chamber gives rise to significant changes on the color and micro-morphology of the foil, featuring dense and long nano-wires. The as-synthesized nanostructures are characterized by various methods and identified as TiN, Ti2N, and TiO2 respectively. Moreover, the experiment results show that oxide nanowire has a high degree of crystallinity and the nitrides present specific orientation relationships with the titanium matrix.

Spontaneous formation of Au-Co interface via a Low-Temperature reduction process

Eutectic alloys manufactured by metallurgical methods are widely used in many industrial applications due to their special properties provided by the multi-phase eutectic microstructure. Previous studies introduced the preparation of metals and alloys through the chemical reduction of metal complex salts. We employed this technique to prepare the equiatomic composition in the binary eutectic system Au-Co through a low-temperature solid-gas phase reduction of two precursors: the bi-metallic complex salt [Co(NH3)6][AuCl4]Cl2, and an equimolar mixture of H[AuCl4] and pre-reduced cobalt. Complete reduction at 350 °C resulted in the formation of a close-to-equilibrium two-phase composition of fcc gold and hcp cobalt. The structure of the fully reduced metallic materials was composed of interconnected cobalt ligaments and bi-metallic Au-Co (gold-cobalt) particles. Specifically, these spontaneously formed particles featured fcc cobalt islands interfacing with fcc gold at a specific orientation relationship. Under heating, the fully reduced Au-Co products underwent melting that corresponds to the equilibrium eutectic melting point at 996.5 °C. These results imply that spontaneous lattice self-adjustment can occur in multi-component eutectic-type systems at low temperatures directly in the solid state. This may ease the technologies of joining such as epitaxial growth, additive manufacturing, and powder metallurgy.

Novel (Ti, W)C–SiC–WSi2 ceramics fabricated via in situ reaction spark plasma sintering at 1600 °C

Novel (Ti, W)C–SiC–WSi2 ceramics were fabricated by in situ reaction spark plasma sintering (SPS) at 1600 °C using (Ti, W)C and Si powders. The effect of Si content on densification behavior, microstructures, and mechanical properties was investigated. The in situ reaction and the formation of carbon vacancies reduced the sintering temperature. The densification mechanism of (Ti, W)C-based ceramics transforms from reaction to grain-boundary sliding and diffusion. The WSi2 and primary SiC generated by in situ reactions are distributed along the grain boundaries and have a specific crystallographic orientation relationship. Intragranular secondary SiC formed because of rapid densification, grain-boundary diffusion, and (Ti, W1−y)C1−x particle migration. This multiscale particle-reinforced microstructure can improve the mechanical properties of (Ti, W)C ceramics, giving the TW10S (4.80 wt% SiC–5.01 wt% WSi2) good sintering performance, a fine-grained microstructure, high hardness (23.3 ± 1.6 GPa), and flexural strength (425 ± 24 MPa). The SiC and WSi2 produced through in situ reactions have exceptional intrinsic oxidation resistance, allowing the ceramics to achieve outstanding oxidation resistance.

Single-crystal Cu(1 1 1) foil preparation by direct bonding technology

Considering the significant advantages of single-crystal Cu(111) in the synthesis of 2D materials and many other fields, its controllable preparation has attracted widespread attention. However, the formation of a single-crystal Cu foil has always been hindered by competition among grains with different orientations. Herein, single-crystal Cu(111) was prepared on the basis of the traditional direct bonding copper method. Cu foil and c-plane sapphire substrate were bonded through Cu2O at high temperature. After the reduction of Cu2O by H2, the surface crystal structure of sapphire will guide Cu to form single-crystal Cu(111). The single-crystallinity of Cu(111) and the specific orientation relationship between Cu(111) and sapphire were confirmed by LEED and XRD. Furthermore, the growth of high-quality single-crystal graphene was performed on single-crystal Cu(111). This work not only facilitates the mass production of 2D materials such as single-crystal graphene, but also provides greater application potential to the direct bonding copper technology and single-crystal Cu.

Controllable reinforcement phase distribution at the grain scale via a simple precipitation process

Due to the inability of Zr to refine Al-containing Mg alloys, achieving pronounced grain refinement in cast AZ31 alloy has been a significant challenge for researchers. Surprisingly, we found that the reinforcement phases demonstrated a regular distribution at the grain scale after adding 0.9 wt% Nd and 0.3 wt% Y: Al2RE inside the grains and Al11RE3 agglomerated near the grain boundaries. Additionally, the grain size of AZ31 alloy was significantly reduced from 258 µm to 65 µm. The mechanisms of reinforcement phase distribution and grain refinement were explored through the combination of transmission electron microscope (TEM) and thermal analysis during the solidification process. Al2RE phase precipitates prior to α-Mg, and exhibits a specific orientation relationship with the matrix: 011̅0Mg∥011Al2RE，0002Mg∥22̅2Al2RE. This suggests that Al2RE serves as potentially effective heterogeneous nucleation sites for α-Mg. Moreover, Al11RE3 phase can restrict grain growth in the later stage of solidification. The tensile results show that a regular distribution of the reinforcement phase at the grain scale can not only effectively alleviate stress concentration, but suppress the formation of coarse twins by inducing grain refinement during alloy solidification process, significantly improving the strength and ductility of the alloy.

Microstructure evolution and lath martensite precipitation behavior of Co@GNPs/CoCrMo composites fabricated by selective laser melting

Spherical cobalt nanoparticles were reduced and deposited in situ on the graphene (GNP) surface using a novel hydrothermal method, and the prepared Co@GNPs reinforced powder were uniformly dispersed in the alloy matrix. The Co@GNPs/CoCrMo composite fabricated using selective laser melting (SLM) was densely organized with reduced hole defects, and fine equiaxed grains, elongated columnar grains, and duplex ε + γ were observed in the composite organization. Meanwhile, a high density of dislocations and nanoscale stacked layer dislocations were observed at the equiaxed grain boundaries. Further, the GNPs acted as heterogeneous nucleation sites, which promoted the transformation of the γ-Co (FCC) austenite phase to the ε-Co (HCP) martensite phase by means of slip. A unique characteristic structure of nanoscale parallel-arranged lath martensite is formed on the surface of GNPs. Therefore, a co-lattice structure between ε-co and γ-co shows the specific orientation relationship between the crystallographic plane (1 1 1)γ-co//(0 0 0 2)ε-co and the crystallographic zone axis [1 1 0]γ-co//[1 1 2‾ 0]ε-co.

Effect of austenitizing temperature on martensitic transformation in SA508Gr.4N steel

SA508Gr.4 N steel is commonly used in nuclear pressure vessels. The current study discloses the impact of austenitizing temperature on its martensitic transformation. Various austenitizing temperatures were employed to examine the martensitic transformation at different experimental conditions. The characteristics of grain boundaries, microstructure, transformation kinetics, and crystallography of the martensitic phase following the austenitizing process and martensitic transformation were analyzed. Austenitizing temperatures had minimal effects on the critical temperature of the austenitizing phase transition. However, an increase in austenitizing temperature resulted in larger grain sizes. The phase composition primarily consisted of lath martensite, accompanied by a small amount of residual austenite (RA). As the austenitizing temperature increased, the temperature of martensite-start temperature (Ms) initially decreased and then increased. On the other hand, the temperature of martensite-finish (Mf) showed no significant sensitivity to changes in the austenitizing temperature. Moreover, the average size of the lath martensite structure was increased, and there was an increased tendency for variant selection as the austenitizing temperature increased, and the combination of specific orientation relationships appeared. This study is very valuable for revealing the microstructure evolution at different temperatures.

Crystallography of stress-induced martensitic transformation and giant elastocaloric effect in a A textured Ni27Cu21Mn46Sn6 shape memory alloy

Shape memory alloys exploit the latent heat yielded by stress-induced martensitic transformation to achieve elastocaloric effect, being suited for solid-state cooling technology as an alternative to conventional vapor-compression refrigeration. In this work, the crystallography of stress-induced martensitic transformation and elastocaloric effect in a polycrystalline Ni27Cu21Mn46Sn6 shape memory alloy with <001>A preferential orientation produced by means of directional solidification were studied. By performing ex-situ electron backscatter diffraction (EBSD) measurements, the transition from austenite to a single variant of 6 M martensite induced by compressive loading was evidenced, following a specific transformation orientation relationship of {1 0 1}A//{1 –2 –6}M and <1 0 − 1>A//<–6 –6 1>M between two phases. Moreover, owing to the synergistic effect of large transformation entropy change tailored through manipulating the lattice volume change across the phase transformation and microstructure texturing promoted by temperature gradient effect during solidification process, the present alloy can demonstrate very remarkable elastocaloric effect, with an extremely high value of adiabatic temperature variation up to –31.8 K upon releasing a moderate compressive loading of 460 MPa. This work is expected to give insight into stress-induced martensitic transformation crystallography and offer some inspirations for designing high-performance elastocaloric materials.

Examination of NCSL (near-coincidence site lattice) structures formed during β2 (Ni3-xTe2) precipitation in diffusion-bonded PbTe-Ni interfaces – A TEM study

Establishing dependable interconnects within thermoelectric (TE) modules is of utmost significance in ensuring the longevity and functionality of these solid-state devices. PbTe-based devices are used in mid-temperature range applications, with Ni being the most preferred interconnect. The available literature has focused primarily on optimizing the joining parameters. However, fine microstructural features have not been reported that can affect the local semiconducting and mechanical properties. This research paper presents novel findings regarding the formation of previously undiscovered fine (Ni3-xTe2) β2 precipitates resembling Widmanstätten morphology within the PbTe matrix during joining processes. PbTe and Ni discs are diffusion bonded at 600 °C for various holding times. The precipitation is studied through advanced analytical TEM/STEM techniques. The current study leads to two noteworthy observations: 1) specific orientation relationships were discovered between the two phases: [001] PbTe ‖ [001] β2, (020) PbTe ‖ (210) β2 and growth directions were along 〈100〉 in PbTe matrix phase. 2) Formation of near-coincidence site lattice (NCSL) structures occurring periodically at the growing fronts of these precipitates. Atomic scale lattice strain mapping indicates a cyclic state of compression and tension at these interfaces. These findings shed light on local composition changes and strain fields within the PbTe matrix during fine β2 precipitation, which has the potential to impact interface reliability.

Strain-induced precipitation behaviors of 7Mo super-austenitic stainless steel

Strain-induced precipitation (SIP) behaviors of 7Mo super-austenitic stainless steel (SASS) were studied by strain relaxation test at 850 °C. Our results reveal that sigma (σ) phases are the predominant SIP of 7Mo SASS, with the chemical formula of (FeNi) (CrMo). SIP first precipitates in granular shape at HAGBs, such as deformed grain boundaries (SIP-GBs), interfaces between deformation twin layers and matrix (SIP-TW), and HAGBs inside deformed grains (SIP-HAGBs). This is attributed to the ability of HAGBs for providing high deformation stored energy, nucleation sites, and efficient element diffusion channels. When the nucleation sites at HAGBs become saturated with increasing holding time, needle-like SIPs (SIP-NL) are precipitated along closely packed planes of γ-Fe matrix. The specific orientation relationships between SIP-NL and matrix, namely (−111)γ-Fe//(00–1)σ, [0–11]γ-Fe//[-110]σ or (-1-1-1)γ-Fe//(00–1)σ, [0–11]γ-Fe//[-110]σ, and the needle-like shape are contribute to minimizing interfacial energy and elastic strain energy of SIP, respectively, thereby promoting SIP-NL. The absence of SIP on dislocations can be attributed to the large critical nucleus size of σ phase (about 4.87 nm), which poses challenges for SIP nucleation through dislocation distortion energy. Mo is the controlling element for the nucleation and growth of SIP. SIP can promote cDRX through particle-induced nucleation (PSN) mechanism during the deformation process, while residual high-density dislocations around SIP can also promote cSRX during the holding process. During holding process, the boundaries of recrystallized grains can also serve as nucleation sites for SIP, thereby promoting SIP, and finally form a multi-layer structure of “σ phase/Recrystallization/σ phase”.

Microstructural evolution and wear properties of in-situ (TiB + TiC)-reinforced Ti6Al4V matrix composite coating by laser melting deposition

In this study, a laser melting deposition (LDM) process was employed to deposit titanium matrix composite (TMC) coatings on a titanium alloy substrate by adding 1–5 wt% nanosized B4C particles, which were annealed at 900 °C. The microstructure and dry sliding friction behavior of TMC coatings were studied before and after the annealing treatment. The experimental results show that the TiB + TiC hybrid reinforced phase formed by the in-situ reaction of B4C and Ti matrix mainly precipitated at the grain boundary, providing the grain boundary and second-phase strengthening. Specific orientation relationships of TiB and TiC phases with the matrix phase were revealed, which had an essential effect on the microhardness distribution along the coatings. The annealing treatment promoted the diffusion of hybrid reinforcement into the matrix, strengthening their interface bonding, and has an significant impact on the wear properties of TMC coating. The room temperature friction coefficient (COF) of all the coatings remained relatively constant at 0.3–0.6. With increasing B4C content, the wear loss of the as-deposited coatings continually increased from 0.024 mm3 to 0.054 mm3, while the wear loss of the annealed TMC coatings are much lower than before, from 0.032 mm3 (TMC1) to 0.020 mm3 (TMC2) and then rise to 0.023 mm3 (TMC3). Scanning electron microscopy (SEM) morphologies determined that annealing reduced the abrasive and adhesive wear of TMC composite coating and improved its wear resistance.

Effect of Y Content on Precipitation Behavior, Oxidation and Mechanical Properties of As-Cast High-Temperature Titanium Alloys

To improve the heat resistance of titanium alloys, the effects of Y content on the precipitation behavior, oxidation resistance and high-temperature mechanical properties of as-cast Ti-5Al-2.75Sn-3Zr-1.5Mo-0.45Si-1W-2Nb-xY (x = 0.1, 0.2, 0.4) alloys were systematically investigated. The microstructures, phase evolution and oxidation scales were characterized by XRD, Laser Raman, XPS, SEM and TEM. The properties were studied by cyclic oxidation as well as room- and high-temperature tensile testing. The results show that the microstructures of the alloys are of the widmanstätten structure with typical basket weave features, and the prior β grain size and α lamellar spacing are refined with the increase of Y content. The precipitates in the alloys mainly include Y2O3 and (TiZr)6Si3 silicide phases. The Y2O3 phase has specific orientation relationships with the α-Ti phase: (002)Y2O3 // (1¯1¯20)α-Ti, [110]Y2O3 // [4¯401]α-Ti. (TiZr)6Si3 has an orientation relationship with the β-Ti phase: (022¯1¯)(TiZr)6Si3 // (011)β-Ti, [1¯21¯6](TiZr)6Si3 // [044¯]β-Ti. The 0.1 wt.% Y composition alloy has the best high-temperature oxidation resistance at different temperatures. The oxidation behaviors of the alloys follow the linear-parabolic law, and the oxidation products of the alloys are composed of rutile-TiO2, anatase-TiO2, Y2O3 and Al2O3. The room-temperature and 700 °C UTS of the alloys decreases first and then increases with the increase of Y content; the 0.1 wt.% Y composition alloy has the best room-temperature mechanical properties with a UTS of 1012 MPa and elongation of 1.0%. The 700 °C UTS and elongation of the alloy with 0.1 wt.% Y is 694 MPa and 9.8%, showing an optimal comprehensive performance. The UTS and elongation of the alloys at 750 °C increase first and then decrease with the increase of Y content. The optimal UTS and elongation of the alloy is 556 MPa and 10.1% obtained in 0.2 wt.% Y composition alloy. The cleavage and dimples fractures are the primary fracture mode for the room- and high-temperature tensile fracture, respectively.

Habit plane determination from reconstructed parent phase orientation maps

This study details the development and validation of a new algorithm that determines the dominant habit plane of a transformed child phase from orientation maps of a single planar cross-section. The method describes the habit plane in terms of its five-parameter grain boundary character and couples it to the specific orientation relationship of the identified orientation variant. The symmetry operations associated with the specific orientation relationship of the variants are applied to transform habit plane traces as determined in the specimen-fixed reference frame into the parent or child reference frame, allowing for the fitting of the habit plane. Our algorithm stands out by its robustness, computational efficiency, automation and ability to operate on fully transformed microstructures. Four automated methods for habit plane trace determination are proposed and compared. Detailed sensitivity analysis reveals that the proposed algorithm is exceptionally robust against poor accuracy in the measured traces and distortions in the orientation map, but more sensitive to inaccuracies propagated from parent grain reconstruction. Validation on a synthetic microstructure with a known habit plane returned consistent results when applied to high and low carbon steels with different prior austenite grain sizes and orientation map resolutions. The habit planes were not significantly affected by the austenite grain sizes. The habit plane of the steel with 0.35 wt% C was close to (111)γ whereas the habit plane of steel with 0.71 wt% C was closer to (575)γ, in close agreement with previous work using two-surface stereological analysis and transmission electron microscopy-based trace analysis.