Christoph Kirchlechner

• Professor
• Karlsruhe Institute of Technology

Differentiation of granular bainite and polygonal ferrite in high-strength low-alloy (HSLA) steels possesses a significant challenge, where both nanoindentation and chemical analyses do not achieve an adequate phase classification due to the similar mechanical and chemical properties of both constituents. Here, the kernel average misorientation fro...

Motivated by advances in flexible electronic technologies and by the endeavour to develop non-destructive testing methods, this article analyses the capability of computational multiscale formulations to predict the influence of microscale cracks on effective macroscopic electrical and mechanical material properties. To this end, thin metal films u...

Bulk MAX phase materials were investigated heavily in the last decades due to their advantageous combination of metallic and ceramic properties. In recent years, MAX phases also gained the interest of the protective coatings community. Cr2AlC is a very promising material, since the crystalline MAX phase can be deposited at comparatively low (550 °C...

Pop-in statistics from nanoindentation with spherical indenters are used to determine the stress required to activate dislocation sources in twin boundaries (TBs) in copper and its alloys. The TB source activation stress is smaller than that needed for bulk single crystals, irrespective of the indenter size, dislocation density and stacking fault e...

In this work, we experimentally establish the isothermal nanofacet evolution at an asymmetric ∑5 tilt grain boundary in the Cu-Ag system using a diffusion couple approach. We investigate the nanofacet formation along the grain boundary in dependence of the Ag solute excess concentration. The initial grain boundary dissociates into asymmetric Ag-lea...

Molecular dynamics simulations are performed to investigate the role of a coherent {\Sigma}3 (111) twin boundary on the plastic deformation behavior of Cu nanopillars. Our work reveals that the mechanical response of pillars with and without the twin boundary is decisively driven by the characteristics of initial dislocation sources. In the conditi...

Understanding the orientation-dependent deformation behavior of NiTi shape-memory alloys at small length scales is of importance for designing nano- and micro-electromechanical systems. However, a complete understanding of the orientation- and size-dependent competition between the various modes of slip, deformation twinning, and martensitic transf...

An optimised micro-shear testing protocol was adopted to measure the critical resolved shear stresses for basal and pyramidal I slip systems in pure magnesium. The micro-shear samples are carefully aligned for basal and pyramidal I slip by electron backscatter diffraction and fabricated by focussed ion beam milling. In situ scanning electron micros...

We have performed micro pillar compression to investigate the influence of strain rate on the activation of three slip plane families, namely {110}, {112} and {123}, in ferrite of a dual phase steel. The critical resolved shear stress of all three slip plane families rises with increased strain rate. The strain rate sensitivity drops with increasin...

In this work, we experimentally establish the isothermal nanofacet evolution at an asymmetric tilt grain boundary in the Cu-Ag system using a diffusion couple approach. We investigate the nanofacet formation along the grain boundary in dependence of the Ag solute excess concentration. The initial grain boundary dissociates into asymmetric Ag-lean s...

Wafer curvature measurements reported in literature for polycrystalline (often textured) and epitaxial fcc metal thin films on hard substrates show a characteristic “signature” in the stress-temperature evolution for either type of films. While epitaxial films reveal characteristic elastic – ideal plastic deformation with no dislocation storage and...

Molecular dynamics simulations are performed to investigate the impact of a coherent Σ3 (111) twin boundary on the plastic deformation behavior of Cu nanopillars. Our work reveals that the mechanical response of pillars with and without the twin boundary is decisively driven by the characteristics of initial dislocation sources. In the condition of...

The mechanical properties of high-entropy alloys (HEAs) are still not deeply understood. Detailed knowledge of the strengthening mechanism, especially, the atomistic origin of solid solution hardening and its interplay with dislocation plasticity is needed. Here, we report on the dislocation glide behavior of a FeCoCrNiMn face-centered cubic (FCC)...

Experimental fracture mechanics at the microscale became an indispensable tool for understanding and developing advanced material systems. In case of linear elastic fracture mechanics, stringent requirements are typically only warranted for very brittle materials. The material properties of semi-brittle materials might be accessible by elasto-plast...

Microscale mechanical behaviour of single crystalline Barium Titanate (BaTiO3), a ferroelectric ceramic was studied by uniaxial in situ micropillar compression and nanoindentation. It was observed that pillars below 1 µm diameter reached the theoretical strength of BaTiO3 whereas larger pillars yielded at lower stress values with multiple stress dr...

Quantum mechanically guided materials design has been used to predict the mechanical property trends in crystalline materials. Thereby, the identification of composition-structure-property relationships is enabled. However, quantum mechanics based design guidelines and material selection criteria for ultra-strong metallic glasses have been lacking....

The interfacial fracture toughness of sintered hybrid silver nanoparticles (AgNPs) on both Au and Cu substrates is studied as a function of sintering temperature. Interfacial microstructure and porosity evolution of Au/AgNPs and Cu/AgNPs are observed to impact the fracture toughness. An Au–Ag interfacial diffusion layer is resolved at the interface...

This paper investigates the interdependence of the stacking fault energy (SFE) and the stress required for dislocation multiplication. For this purpose copper-aluminum (Cu-Al) alloys with varying Al content are investigated by spherical nanoindentation. The load-displacement curve shows a characteristic pop-in, which is interpreted as elastic-plast...

In hard coating development there is a need for fast and efficient screening methods to assess the influence of changes in composition and structure evolution on the mechanical behavior. Nanoindentation constitutes a method that allows fast and efficient probing of mechanical properties. For another important mechanical characteristic of hard coati...

A photolithographic process for the rapid fabrication of thin-film tensile-test structures is presented. The process is applicable to various physical vapor deposition techniques and can be used for the combinatorial fabrication of thin film tensile test structure materials libraries for the high throughput characterization of mechanical properties...

In conventional metallic materials, strength and ductility are mutually exclusive, referred to as strength-ductility trade-off. Here, we demonstrate an approach to improve the strength and ductility simultaneously by introducing micro-banding and the accumulation of a high density of dislocations in single-phase high-entropy alloys (HEAs). We prepa...

We study the effects of transformation-induced plasticity (TRIP) on the micrometer-scale deformation of single crystalline pillars. Plastic deformation mechanisms (i) mediated by pure dislocation glide and (ii) strain-induced epsilon-martensite transformation are separated using compositionally complex model alloys. The results show that transforma...

Extended diffusion layers of the cubic C15 and hexagonal C14 and C36 NbCo 2 Laves phases with concen- tration gradients covering their entire homogeneity ranges were produced by the diffusion couple tech- nique. Single-phase and single-crystalline micropillars of the cubic and hexagonal NbCo 2 Laves phases were prepared in the diffusion layers by f...

Composition dependence of hardness and elastic modulus of the cubic and hexagonal NbCo2 Laves phase polytypes studied by nanoindentation - Volume 35 Issue 2 - Wei Luo, Christoph Kirchlechner, Juan Li, Gerhard Dehm, Frank Stein

Compression of micropillars is followed in situ by a quick nanofocused X‐ray scanning microscopy technique combined with 3D reciprocal space mapping. Compared to other attempts using X‐ray nanobeams, it avoids any motion or vibration that would lead to a destruction of the sample. The technique consists of scanning both the energy of the incident n...

Energy dispersive X-ray Laue diffraction is applied to investigate the deformation behavior of individual grains in a polycrystalline nickel wire under tensile loading. 38 Laue spots are identified in the Laue pattern which originate from 9 separate grains. The simultaneous measurements of the Laue spot's position and energy obtained by using a 2D...

In modern multiphase materials, damage initiation and growth during plastic deformation is a commonly observed and technologically relevant process. To reliably assess the state of damage in a specimen or, ultimately, a formed product, precise and comparable damage quantification is required. Furthermore, the key to understanding the initiation and...

High fracture toughness is crucial for the application of metallic glasses as structural materials to avoid catastrophic failure of the material in a brittle manner. One fingerprint for fracture toughness in metallic glasses is the fraction of hybridized bonds, which is affected by alloying Pd57.4Al23.5Y7.8M11.3 with M = Fe, Ni, Co, Cu, Os, Ir, Pt,...

We used micropillar compression experiments to study the plasticity of ferrite and martensite of two commercial dual phase steel grades (DP800). The activation of all three slip plane families, namely {110}, {112}, {123}, was observed in single crystalline ferrite pillars. They exhibit a comparable mean critical resolved shear stress (CRSS) of 147...

Perfect slip transfer through single coherent Σ3 twin boundaries is known to be a cross-slip-like mechanism occurring at low stresses, which is expected to strongly depend on material properties like stacking fault energy. In the present study, we extend the argument of perfect slip transfer to (i) multiple closely spaced coherent twin boundaries i...

Transient liquid phase bonding offers one option to generate a robust lead-free die attach with sound thermal and electrical conductivity in microelectronic packages. However, it is a challenge to characterize the microstructure and mechanical behavior of the bonding layer because of its ultra-thin thickness and its nano-sized constituents. We show...

Laves phases are intermetallic phases well known for their excellent strength at high temperatures but also for their pronounced brittleness at low temperatures. Especially in high-alloyed steels, Laves phases were long time regarded as detrimental phases as they were found to embrittle the material. Perusing the more recent literature, it seems th...

Failure in engineering materials like steels is strongly affected by in-service deleterious alterations in their microstructure. White Etching Layers (WELs) are an example of such in-service alterations in the pearlitic microstructure at the rail surface. Cracks initiate in the rails due to delamination and fracture of these layers and propagate in...

The study of mechanical properties of materials at high temperatures at the microstructural length regime requires dedicated setups for testing. Despite the advances in the instrumentation in these setups over the last decade, further optimization is required in order to extend the temperature range well-beyond 600 °C. Particularly, an improvement...

Impact of in situ nanomechanics on physical metallurgy - Volume 44 Issue 6 - J. Kacher, C. Kirchlechner, J. Michler, E. Polatidis, R. Schwaiger, H. Van Swygenhoven, M. Taheri, M. Legros

Load-displacement curves with spherical indenters often exhibit a so-called pop-in, which can be interpreted as elastic-plastic transition due to activation or even nucleation of dislocation sources. Due to the stochastic nature of deformation at the micron scale a wide distribution of pop-in loads (referred as pop-in statistics) can be observed. T...

The fracture behavior of a white etching layer formed on the rail surface in pearlitic steels during the rail-wheel contact is investigated using indentation-based microcantilever fracture tests. The sample thickness is in the order of 5 μm. The local fracture toughness of the white etching layer, its neighboring brown etching layer, martensite and...

The important role of grain boundaries for the mechanical properties of polycrystalline materials has been recognized for many decades. Up to now, the underlying deformation mechanisms at the nano- and micro scale are not understood quantitatively. An overview of the synthesis and subsequent mechanical testing of specific grain boundaries at the mi...

MPIE has investigated spontaneous formation of martensite from ultimately deformed pearlite nanostructure. Pearlite steel wire with its plate structure from cubic volumetric-centered ferrum and cementite (Fe3C) is subjected to cold drawing and becomes thinner; its microstructure varies as well - it is getting more fi ne and, at the same time, gradu...

We show that chemistry can be used to trigger a nanofaceting transition. In particular, the segregation of Ag to an asymmetric tilt grain boundary in Cu is investigated. Aberration-corrected electron microscopy reveals that annealing the bicrystal results in the formation of nanometer-sized facets composed of preferentially Ag-segregated symmetric...

Nanoindentation tests have shown that exposure to deuterium plasma causes a decrease in pop-in load and an increase in hardness of tungsten. In this work, we use micro-compression tests to investigate the plastic deformation and apparent strain hardening of tungsten exposed to deuterium plasma. In comparison with the pillars tested at reference sta...

We unravel the nature of twin boundary-associated strengthening in Fe-Mn-C twinning-induced plasticity steel (TWIPs) by micro-pillar compression tests. Dislocation interactions with a coherent twin boundary and their role on strain hardening were investigated. The results indicate that twin-matrix bundles dynamically introduced by deformation twinn...

Hydrogen exposure has been found to result in metal embrittlement. In this work, we use nanoindentation to study the mechanical properties of polycrystalline tungsten subjected to deuterium plasma exposure. For the purpose of comparison, nanoindentation tests on exposed and unexposed reference tungsten were carried out. The results exhibit a decrea...

We present the first measurement of the strain rate sensitivity of the ideal dislocation slip transmission through a coherent Σ3{111} copper twin boundary. For this purpose we have deformed 129 geometrically identical samples at different strain rates. The micron-sized samples are either single crystalline (87 pillars) or contain one vertical Σ3{11...

Cu/Nb nanoscale metallic multilayers have been extensively investigated to understand how their mechanical behavior is influenced by the individual layer thickness. The general observed trend is that the yield stress of the multilayer increases with decreasing layer thickness. Important mechanical behaviors that have not been studied in-depth are t...

We report the enhancement of fracture toughness and strength of a cobalt‑tantalum-based metallic glass thin film with increasing boron content. The improvement of the mechanical performance is attributed to the formation of a compositionally lamellar compared to uniform glass microstructure, which becomes thinner with increasing boron content as re...

The microstructural and mechanical characterization of an equiatomic YGdTbDyHo high entropy alloy with hexagonal close-packed structure was performed. The phase state and chemical homogeneity of the solid solution were analysed with respect to crystal structure, phase stability, and oxide formation. It was found that Y-rich precipitates form at gra...

The fracture behaviour and microstructure evolution of sputtered Mo2BC films as a function of their deposition temperature is studied. Bipolar pulsed direct current magnetron sputtering was used to deposit Mo2BC thin films onto Si (100) wafers at substrate temperatures ranging from 380 to 630 °C. Microstructural characterization by transmission ele...

Cubic and hexagonal NbCo2 Laves phases are known to have composition dependent hardness and yield strength. However, it is unknown whether this dependence is also reflected in their fracture toughness values. In order to elucidate the fracture behavior, single-crystalline micro-cantilevers of the cubic and hexagonal NbCo2 Laves phases having differ...

A composition-spread Cu-Zr thin film library with Zr contents from 2.5 up to 6.5 at.% was synthesized by magnetron sputtering on a thermally oxidized Si wafer. The compositional and microstructural variations of the Cu-Zr thin film across the composition gradient were examined using energy dispersive X-ray spectroscopy, X-ray diffraction, and high-...

Micro pillar compression is used to analyze the strain rate dependence of copper pillars containing a penetrable high-angle grain boundary via in situ compression tests at strain rates ranging from 10− 1 to 10− 4 s− 1. While the grain-boundary containing pillars exhibit a clear strain-rate dependence of m = 0.04 ± 0.02, their single crystal counter...

In situ micro-cantilever fracture testing is used to demonstrate changes in fracture behavior of nanostructured, heavily cold drawn pearlitic steel wires as a function of drawing strain and annealing conditions. It is shown that these steels exhibit a sharp transition in fracture behavior between a drawing strain of 320% and 520% with a drop in fra...

When ductile metal films on compliant polymer substrates are strained in tension catastrophic failure can be suppressed by the substrate, thus allowing for their use in flexible electronics and sensors. However, the charge carrying ductile films must be of an optimum thickness and microstructure for the suppression of cracking to occur. Studies of...

Focused ion beam machined microcantilevers are frequently used for fracture mechanics analysis of inhomogeneous solids at the micrometer scale. A finite element method study about the influence of the pre-crack geometry on the apparent fracture toughness is provided. We discuss the influence of material bridges and the effect of rounded pre-crack c...

In-situ TEM Study of Mechanical Size Effects in TiC Strengthened Steels - Volume 23 Issue S1 - S. Taniguchi, R. Soler, C . Kirchlechner, C. Liebscher, A. Taniyama, G. Dehm

The in situ characterization of the deformation and fracture behavior of brittle metal films is of great technological interest for many modern applications. A prominent example is the field of flexible electronics, which rely on the electrical and mechanical integrity of metal thin films on compliant substrates when exposed to straining or bending...

The full strain and stress tensor determination in a triaxially stressed single crystal using X-ray diffraction requires a series of lattice spacing measurements at different crystal orientations. This can be achieved using a tunable X-ray source. This article reports on a novel experimental procedure for single-shot full strain tensor determinatio...

Micro- and nanomechanical testing has seen a rapid development over the last decade with miniaturized test rigs and MEMS-based devices providing access to the mechanical properties and performance of materials from the micrometer down to the tenths of nanometer length scale. In this overview, we summarize firstly the different testing concepts with...

The implications of various size effects on the deformation behavior of and near grain boundaries is not yet fully understood. In this manuscript, slip transfer mechanisms through a general high angle grain boundary (HAGB) allowing for easy transfer are investigated in order to understand the size dependence of the dislocation-grain-boundary intera...

It is the aim of this paper to show the mechanisms behind the experimental observations of rather smooth sigmoidal deformations in bi-crystal micropillar tests (in contrast to single crystal micro-compression tests) and to point out that the appearance of such deformation modes are a further reason for being careful when interpreting the force-axia...

Deformation twinning contributes to a high work-hardening rate through modification of the dislocation structure and a dynamic Hall-Petch effect in polycrystalline steel. Due to the well-defined compression axis and limited deformation volume of micro-pillars, micro-compression testing is a suitable method to investigate the mechanisms of deformati...

The size dependence of the mechanical behavior of a single crystalline equiatomic FeCrCoMnNi single phase high entropy alloy was studied using in situ SEM microcompression. Electron back-scattered diffraction was used in conjunction with high-resolution scanning electron microscopy to identify the dominant slip system activated for accommodating pl...

Compression of micropillars is routinely used to measure the material response under uniaxial load. In bi-crystalline pillars an S-shaped grain-boundary together with an S-shaped pillar is often observed after deformation raising the question of its origin and consequences for stress-strain materials data. In addition to dislocation and grain-bound...

The mechanical behavior of several micron sized Cu bi-crystals with a single coherent twin boundary (TB) is studied by in situ Laue microdiffraction (μLaue) compression with the aim to unravel the slip transfer mechanisms through TBs. Single crystalline pillars (SCP) are additionally tested and used as reference samples. Engineering stress-strain c...

Uchic and co-workers were the first ones who performed uniaxial compression tests on micron-sized samples and inspired scientists worldwide to perform similar microcompression, tension, or bending experiments. The straining device is able to perform compression, tensile, or bending experiments. Complementary fine energy scans can be performed by in...

Miniaturized fracture beam experiments are often used to identify the fracture toughness of single phases and particular grain boundaries because large-scale experiments reveal only homogenized material properties. The evaluation of the microscale toughness is based on isotropic 2D models although the majority of materials are anisotropic. Moreover...

The effect of film thickness as well as the influence of heat treatment on the deformation behavior of thin cobalt films (50–2000 nm) on polyimide substrates was investigated using various tensile tests. Straining under an optical light microscope provides information about the fracture strain and cracking behavior. The annealed films exhibit enhan...

Driven by legislation and the abolishment of harmful and hazardous lead-containing solders, lead-free replacement materials are in continuous development. Assessment of the mechanical properties of intermetallic phases such as Cu3Sn that evolve at the interface between solder and copper metalization is crucial to predict performance and meet the hi...

The thermal stability of evaporated copper–chromium alloy films was studied by correlating hardness trends from nanoindentation to nanostructural–compositional changes from transmission electron microscopy. In particular, the hardness evolution with ageing time at ambient and elevated temperatures of two compositions, dilute (Cu96Cr4) and chromium-...

Most of the nowadays used structural materials are of polycrystalline nature since single crystal fabrication is very cost intensive and sometimes not even desired. For instance, increasing the internal interface fraction – like grain boundaries – is known to strengthen metals significantly according to the Hall‐Petch relation, thereby reducing the...

A paramount challenge in materials science is to design damage-tolerant glasses. Poisson’s ratio is commonly used as a criterion to gauge the brittle-ductile transition in glasses. However, our data, as well as results in the literature, are in conflict with the concept of Poisson’s ratio serving as a universal parameter for fracture energy. Here,...

The strain-induced FCC to HCP phase transformation of a two phase Co film on polyimide was investigated by performing a tensile test in an X-ray diffractometer. During straining of the 2 μm thick film, the intensity of the (002)FCC peak continuously decreases at engineering strains between 2 and 8% and remains constant at higher strains. Complement...

Besides the high spatial resolution achieved in aberration-corrected scanning transmission microscopy, beam-induced dynamic effects have to be considered for quantitative chemical characterization on the level of single atomic columns. The present study investigates the influence of imaging conditions in an aberration-corrected scanning transmissio...

A paramount challenge in materials science is to design damage-tolerant glasses. Poisson's ratio is commonly used as a criterion to gauge the brittle-ductile transition in glasses. However, our data, as well as results in the literature, are in conflict with the concept of Poisson's ratio serving as a universal parameter for fracture energy. Here,...

The micro-mechanical fracture behavior of single crystalline silicon was investigated as a function of temperature in situ in the scanning electron microscope equipped with a nanoindenter. A gradual but continuous increase in KC was observed with increasing temperature above 300 °C, in contrast to the sharp transitions observed in earlier works. No...

Even though lead-free Sn-Ag-Cu based solder alloys are emerging as promising candidates to replace well-established but hazardous lead-containing solders, they suffer from limited knowledge about their mechanical performance. To ensure the high reliability demands in microelectronics, fracture properties need to be quantified with respect to crucia...

As the length scale of sample dimensions is reduced to the micron and sub-micron scales, the strength of various materials has been observed to increase with decreasing size, a fact commonly referred to as the ‘sample size effect’. In this work, the influence of temperature on the sample size effect in copper is investigated using in situ microcomp...

Ultra-High-Energy Laue diffraction was used to investigate polycrystalline nickel wires under external tensile stress. Using broad x-ray beam (compared to grain size) we highlight a method for individual grains identification, indexing, depth profiling, and texture mapping. We trace the response of individual crystallites to the applied tensile str...

Although, tin is one of the most prominent metals in soldering, very little is known about its mechanical behavior. In addition, possible size-effects of tin can become restricting for the ongoing miniaturization of microelectronic devices. Due to the low melting temperature of 505.15 K and the body-centered tetragonal crystal structure, difference...

Statement of significance: Although bio-mechanics of shell structures like nacre have been studied over the past decade, coccospheres present an architecture that is quite distinct and complex. It is a porous cell structure evolved to protect the living algae cell inside it in the oceans, subjected to significant hydrostatic pressure. Despite bein...

Current developments for improving the mechanical properties of metals, including steels, aim at producing nano-structured materials by severe plastic deformation (SPD). [11,12] To this end, cold-drawn pearlitic-steel wires have been very successful, reaching an ultrahigh tensile strength of up to ca. 7 GPa, [13] making them one of the world's stro...

The full strain tensor present in a 2 · 2 · 6 μm3 sized germanium micro pillar was measured by X-ray microdiffraction Laue during in situ loading. Initial orientation gradients, residual strains and diffraction peak streaking were found negligible. The obtained strain values from Laue pattern analysis have been used to calculate the deviatoric stre...

Coherently grown nanolayered TiN/CrN thin films exhibit a superlattice effect in fracture toughness, similar to the reported effect in indentation hardness. We found –by employing in-situ micromechanical cantilever bending tests on free-standing TiN/CrN superlattice films– that the fracture toughness increases with decreasing bilayer period (Λ), re...

Metal films on polymer substrates are commonly used in flexible electronic devices and may be exposed to large deformations during application. For flexible electronics, the main requirement is to remain conductive while stretching and compressing. Therefore, the electro-mechanical behaviour of 200-nm-thick Cu films on polyimide with two different...

Thin metal films on compliant polymer substrates are of major interest for flexible electronic technologies. The suitability of a film system for flexible applications is based on the electro-mechanical performance of the metal film/polymer substrate couple. This study demonstrates how a 10 nm Cr interlayer deteriorates the electro-mechanical perfo...

Mo2BC nanocrystalline coatings were deposited on Cu substrates to compare their mechanical performance with bench-mark TiAlN, and pure Mo, Al and Al2O3 reference coatings. The Mo2BC coatings were characterized by X-ray diffraction and transmission electron microscopy to analyze the microstructure. In order to study the damage behavior, the coatings...

The mechanical behavior of Cu-Cr nanolayered films and an alloy film of nominal composition Cu20Cr80 at.% was studied by microcompression testing at temperatures from 25 °C to 300 °C. Comparing nanolayered films, plastic deformation and failure occurred at consistently higher stress levels in the film with the smaller layer thicknesses. Plasticity...

In situ micromechanical compression tests on Cu pillars were performed to evaluate the influence of twin boundaries on the mechanical behavior. The 1 µm sized Cu samples on a Si substrate prepared by focused ion beam milling were either single crystalline or contained 2–5 twin boundaries that were inclined to the compression direction. The strength...

This file contains an extended abstract for the "Gefüge und Bruch" conference, held in Leoben 04/2015.

The evolution of low cycle fatigue damage in copper is studied by in situ micro Laue diffraction. Free standing single crystalline micro-cantilevers with a cross-section of 10 × 10 μm2 were loaded in displacement controlled mode with a surface strain amplitude up to 5%. The point to point misorientation and the diffraction peak width as a measure o...