Adhesion Mechanical Properties Research Articles

Mechanical Properties of Selected Epoxy Adhesive and Adhesive Joints of Steel Sheets

The article presents the issues of the mechanical properties of epoxy adhesives and the adhesive joints strength of steel sheets which were made using the epoxy adhesives. The aim of the paper is to study the mechanical properties of epoxy adhesive of different epoxy resin/curing agent ratios (within and above the recommended stoichiometric ratio) and their effect on mechanical properties of adhesive joints of steel sheets. In experimental tests three types of epoxy adhesives, containing a low molecular weight epoxy resin based on bisphenol A and polyamide curing agent, were used. A single-lap adhesive joint type of stainless-steel sheets was also applied. Two types of strength test were used: the compressive strength tests (DIN EN 196-1) for epoxy adhesive samples and the shear strength tests (DIN EN 1465) for adhesive joints. Both the analysis of the strength results of the samples of epoxy adhesive and adhesive joints as well as the failure analysis was carried out. On the basis of the results of strength tests it can be stated that the greatest deformation occurred for the samples of epoxy adhesive containing the modified epoxy resin (epoxy number—0.40) and the polyamide curing agent, and the smallest for the samples of epoxy adhesive containing the basic epoxy resin (epoxy number—0.49–0.52) and the polyamide curing agent. The epoxy adhesives with a smaller amount of curing agent were characterized by higher strength. This applies to all analyzed epoxy resins. The same dependences were obtained for the strength of adhesive joints of steel sheets made of the analyzed epoxy adhesive.

Enhancement of the Mechanical and Drug-Releasing Properties of Poloxamer 407 Hydrogels with Casein.

Topical therapy of local disease (e.g. skin) is advantageous over oral therapy since there is less systemic drug distribution (so fewer side-effects), no first-pass effect, etc. However, patient compliance with topical therapy can be poor as it may require many applications a day and can last months. Here we propose a topical controlled release formulation with thermoresponsive gelation at body temperature and improved adhesiveness, making it easier to remain in contact with the body. The formulation contains two excipients, poloxamer 407 (P407) and casein. Casein can modify the properties of the hydrogel through molecular entanglement. In addition, tissue reaction and drug release profile were evaluated. Changes in casein concentration affected adhesive strength, viscosity, mechanical properties and drug release, presumably by hydrophobic interactions between casein and P407. Two different concentrations of P407 were tested with two different concentrations of casein. Formulations containing 5% and 10% casein released 80% of model drug in 48h, while formulations without casein released the same fraction in around 24hhours. Formulations with 10% casein had almost twice the adhesive strength of those without casein. Addition of casein modified the mechanical properties and drug release rate of the hydrogel. There was no inflammation or injury after brief exposure in vivo.

An experimental-numerical methodology for the nondestructive assessment of the dynamic elastic properties of adhesives

In the last years, lightweight design has become a priority in many industrial sectors, like as the aerospace and the automotive industry, mainly due to the strict regulations in terms of gas emission and pollution. Together with lightweight materials, the use of adhesives to join different parts permits to significantly reduce the weight of mechanical assemblies. For a proper design of the joints, the mechanical properties of adhesives should be correctly experimentally assessed. However, the experimental assessment of the adhesive mechanical properties can be complex, since they can be hardly estimated from traditional experimental tests on lap-joint or butt-joint specimens. The development of an experimental procedure for the assessment of the adhesive properties is therefore of interest. In the present paper, a methodology for the assessment of the dynamic elastic properties of adhesives, i.e., Young’s modulus and the loss factor, is proposed. The procedure is based on the Impulse Excitation Technique and Finite Element Analyses (FEA). An automated routine has been written to assess the elastic properties by minimizing the difference between the frequency response obtained experimentally and through FEA. The proposed methodology has been experimentally validated to estimate the mechanical properties of an epoxy adhesive for automotive applications.

Improvements of the structural, thermal, and mechanical properties of structural adhesive with functionalized boron nitride nanoparticles

AbstractInvestigations on the production and development of nanoparticle‐reinforced polymer materials have been attracted attention by researchers. Various nanoparticles have been used to improve the mechanical, chemical, thermal, and physical properties of polymer matrix composites. Boron compounds come to the fore to improve the mechanical and thermal properties of polymers. In this study, mechanical, thermal, and structural properties of structural adhesive have been examined by adding nano hexagonal boron nitride (h‐BN) to epoxy matrix at different percentages (0.5, 1, 2, 3, 4, and 5%). For this purpose, nano h‐BN particles were functionalized with 3‐aminopropyltriethoxysilane (APTES) to disperse the h‐BN nanoparticles homogeneously in epoxy matrix and to form a strong bond at the matrix interface. Two‐component structural epoxy adhesive was modified by using functionalized h‐BN nanoparticles. The structural and thermal properties of the modified adhesives were investigated by scanning electron microscopy and energy dispersion X‐ray spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis techniques. Tensile test and dynamic mechanical analysis were performed to determine the mechanical properties of the adhesives. When the results obtained from analysis were examined, it was seen that the nano h‐BN particles functionalized with APTES were homogeneously dispersed in the epoxy matrix and formed a strong bond. In addition that, it was concluded from the experimental results that the thermal and mechanical properties of adhesives were improved by adding functionalized nano h‐BN particles into epoxy at different ratios.

Зміцнення деталей з алюмінієвих сплавів мікродуговоговим оксидуванням

The purpose of the research is to analyze the scientific and technical information to determine the possibility of strengthening the parts of aluminum alloys by microarc oxidation, in particular gear pump housings. The article presents the results of the analysis of possibility of using a new method of hardening roboczych surfaces - micro-arc oxidation to enhance the wear resistance of working surfaces of parts made of aluminum alloys, in particular housings, gear pumps NSH. The paper describes the essence of the process of hardening parts by microarc oxidation, presents the main physical and mechanical characteristics of the hardening coating. It is noted that the adhesion strength and mechanical properties of the coating largely depend on the state of the surface to be strengthened, in particular, on the method of pretreatment. At the same time, it was found that the strengthening coating of the metal after plastic deformation has a greater adhesion strength, greater thickness and hardness. The paper presents the basic information about microarc oxidation, which, according to the authors, will contribute to the development of the method in the poorly studied method of hardening in repair production. It can be concluded that the ceramic coatings obtained by microarc oxidation can be recommended for the restoration and strengthening of aluminum parts of gear pumps, in particular the pump housing.

Effect of Bias Voltage on Characteristics of Multilayer Si-DLC Film Coated on AA6061 Aluminum Alloy

The multilayer Si-DLC films have been deposited on AA6061 aluminum alloy using a mesh hollow cathode plasma-enhanced chemical vapor deposition technique from acetylene and silane precursor gas at temperature 373 K. Low magnification electron microscopes, Raman spectroscopy, and Fourier transform infrared spectroscopy were employed for characterizing the coating film structure. The MFT-4000 scratch tester, G200 nano-indentation tester, and MS-T3001 tribology tester were utilized to evaluate the adhesion strength, mechanical properties, and friction coefficient. Potentiodynamic polarization and potentiostatic techniques were used to study the multilayer Si-DLC films electrochemical behavior in harsh solution 3.5 wt.% NaCl. The findings revealed that the increase in bias voltage to − 300 V led to the adhesion strength, hardness, elastic modulus, and friction coefficient around 18N, 9.89 GPa, 85.57 GPa, and 0.17, respectively. The polarization results showed a decrease in corrosion current density, increased polarization resistance, and decreased passive current almost 1.28×10−10 A/cm−2, 5.26×109 Ω cm2, and 24.3 nA cm−2, respectively. The findings are ascribed to reduce the internal stress and increase the overall content of sp3 bonds in the film. Moreover, the Si-doped DLC film forms a passive layer from SiOx at the film/solution interface to impede the charge transfer.

ВЛИЯНИЕ ФАЗОВОЙ СТРУКТУРЫ ПОЛИМЕРНОГО ПЛЕНКООБРАЗУЮЩЕГО НА ФИЗИКО-МЕХАНИЧЕСКИЕ И ВЛАГОЗАЩИТНЫЕ СВОЙСТВА ПОКРЫТИЙ

The phase structure, adhesion and physical mechanical properties, water resistance of varnish coatings on the basis of the modified and not modified epoxy filmformers, with organic silicon ammine «AСOT-2» and low-molecular «ПO-200» polyamide as curing agents. It is established that the process of structurization of unfilled epoxy compositions depends on each component of polymeric system. The received results of determination of adhesion, physical mechanical properties, water resistance correlate with results of researches of phase structure of the coatings received on the basis of modified and not modified epoxy compositions, with organic silicon ammine «AСOT-2» and low-molecular «ПO-200» polyamide as curing agents.

Epoxy and epoxy novolac adhesive binders for structural reinforcement systems of building structures

Today, along with the conventional materials and technologies for reinforcement of building structures, structural reinforcement systems based on polymer composites are on the rise. A structural reinforcement system consists of reinforcing filler (normally, carbon fiber fabric or cloth) and adhesive binder. This paper investigated the modification of epoxy nobake adhesive binders to provide a higher thermal resistance and mechanical strength. The influence of epoxy novolac resins on the processing and physical mechanical properties of adhesives, thermal resistance is studied. It is found that the substitution of 20-40 % of epoxy resin for epoxy novolac resin in the binder increases tensile strength by 40-50 %, flexural modulus by 20 %, reduces tensile strain, and increases glass transition temperature. From the processing point of view, it is more reasonable to use liquid epoxy novolac resins with a functionality of f=2.5 than semisolid resins with a functionality of f=3.6.

Microstructural effects of the substrate on adhesion strength and mechanical properties of TiN Thin Films

Microstructure of base material plays an important role in adhesion strength and mechanical properties of Titanium Nitride (TiN) coating especially to increase the lifecycle of parts when in practical use. Present study covers the influence of grain size/microstructure of plain carbon steel (tailored via heat treatment) on TiN thin films deposited by physical vapor deposition (PVD) technique. Strong effect of grain size (microstructure) on adhesion strength of TiN thin films on annealed, normalized and quenched substrates have been observed. Mechanical characterization of TiN films e.g. Elastic modulus (E), Hardness (Hv), Stiffness (S) etc. have been studied via nano-indentation technique. TiN thin films failure investigation has been performed with Micro scratch testing under progressive load. Film exfoliation under critical loads has been corroborated via scanning electron microscopy (SEM). The results showed that TiN films deposited on fine microstructure substrate possess excellent mechanical properties and good adhesion strength as compared to coarser microstructure substrate. Insights of this study might be helpful in designing engineered thin films on optimized microstructures.

Evaluation of the synergistic effect of acetylation and poly(acrylic acid‐co‐2‐hydroxyethyl acrylate) branches on irradiated‐cornstarch for polyester warp sizing

AbstractStarch‐based materials have received great attention for textile warp sizing due to their high modification potentiality, low cost, and biodegradability. However, the brittleness of starch film and low compatibility with polyester has made it challenging to withstand the friction of modern high‐speed weaving machinery. To overcome such drawbacks, a series of irradiated‐cornstarch acetate‐g‐poly (acrylic acid‐co‐2‐hydroxyethyl acrylate) samples with different grafting ratios were designed and prepared in this study. Fourier transform infrared, X‐ray diffraction, and scanning electron microscopy were employed to characterize the structural properties. The prepared starches were cooked for sizing on the roving and spun yarn, for the film formation. The adhesion was evaluated by measuring the bonding force of starch to roving fibers, the abrasion resistance of sized polyester yarn, and water dispersion. Whereas the film properties were investigated in terms of tensile strength, elongation, hydrophilicity, and moisture regain from the air. Results revealed that esterification‐grafting can significantly improve adhesion and film mechanical properties. The enhancement of abrasion resistance reached to 262%. With the increase of grafting ratio, hydratability, water dispersion, and elongation of the film increased, twice as high as that of irradiated‐cornstarch (IS). Desizability was above 88%, reaching the industry standard. The improvement in the warp sizing performance demonstrated that combining acetylation with hydrophilic branches is an effective strategy for the development of high‐performance starch sizing materials.

Design of flexible multi‐level topography for enhancing mechanical property

AbstractRobust mechanical property is fundamentally significant for applications of nano‐materials, such as micro‐fluidic, sensor, superhydrophobic/ icephobic, and crush‐resistant functions. However, the nano‐materials used in the applications are always easily ruined due to the poor adhesion and weak mechanical properties. To enhance the nano‐materials’ duration in hash environment, a strategy of robust nano‐topography protection is studied in this paper. In our experiment, a series of multi‐level sub‐mm topography with nano‐materials are fabricated by integrating the methods of soft lithography, and crystal growth. The mechanical properties of nano‐materials are quantitatively studied, and the nano‐material can be protected by the designed flexible multi‐level topography, which significantly decreases the strain and stress of the nano‐structure. To investigate the mechanism of this performance, a series of simulations are performed, and a mechanical model is established to explain this phenomenon. This work uncovers the multi‐level principles for nano‐materials protection and gives a guideline to design the nano‐materials’ surfaces.

Surface and mechanical properties of adhesives with calcium phosphates challenged to different storage media

Aim: To evaluate the behavior of experimental dental adhesiveswith hydroxyapatite (HAp), alpha-tricalcium phosphate (α-TCP)or octacalcium phosphate (OCP) after storing them in threedifferent media: dry storage, distilled water, or lactic acid.Methods: An experimental adhesive resin was formulated withbisphenol A glycol dimethacrylate, 2-hydroxyethyl methacrylate,and photoiniciator/co-initiator system. HAp (GHAp), α-TCP(Gα-TCP), or OCP (GOCP) were added to the adhesive resin at 2wt.%, and one group remained without calcium phosphates tobe used as a control (GCtrl). The adhesives were evaluated forsurface roughness, scanning electron microscopy (SEM), andultimate tensile strength (UTS) after storing in distilled water(pH=5.8), lactic acid (pH=4) or dry medium. Results: The initialsurface roughness was not different among groups (p>0.05).GHAp showed increased values after immersion in water(p<0.05) or lactic acid (p<0.05). SEM analysis showed a surfacevariation of the filled adhesives, mainly for Gα-TCP and GHAp. GHApshowed the highest UTS in dry medium (p<0.05), and its valuedecreased after lactic acid storage (p<0.05). Conclusions:The findings of this study showed that HAp, OCP, and α-TCPaffected the physical behavior of the experimental adhesiveresins in different ways. HAp was the calcium phosphatethat most adversely affected the surface roughness and themechanical property of the material, mainly when exposed toan acid medium.

Effects of hygrothermal aging on the mechanical properties of aluminum alloy adhesive joints for high-speed train applications

ABSTRACT The mechanical properties of adhesives are sensitive to both temperature and humidity. A modified Arcan device was proposed to characterize the failures of adhesive joints under mixed mode loading. Aluminum alloy butt joints (BJs), 45°scarf joints (45°SJs) and thick-adherend shear joints (TASJs) were manufactured to investigate the effects of loading conditions. Moreover, these joints were subjected to various durations of high-temperature aging (80°C) and hygrothermal aging (80°C/95% RH): 0 (unaged), 6, 12, 18, 24, and 30 days. The adhesive joints were analyzed by Fourier transform infrared (FTIR) spectroscopy, and the load–displacement curves, failure strengths, failure modes were analyzed. The results showed under high-temperature conditions, humidity can accelerate the rate of decrease in the failure strength of the adhesive joints, which resulted from the fracture of the polymer chains and the influence of internal stresses. As the hygrothermal aging duration increased, the fracture surfaces of the joints changed significantly. The number of cracks and cavities in the fracture surface increased as the aging duration increased. After aging, the failure strength values of the adhesive joints conformed to the quadratic stress failure criterion. Two curved surface equations reflecting the relationship between the quadratic stress criterion and the aging duration were established.

Exploration of the enhanced performances for silk fibroin/sodium alginate composite coatings on biodegradable Mg−Zn−Ca alloy

• Silk fibroin/sodium alginate composite coatings were fabricated on MgZnCa alloy without conversion layer via VUV/O 3 activation. • The adhesion force, mechanical property and corrosion resistance were significantly improved by hybrid coating strategy. • The mechanisms for adhesion and corrosion process of the coated structure were proposed. To expand the future clinic applications of biodegradable magnesium alloy, polymer coatings with excellent biocompatibility are the keys to solve the local alkalinity and rapid hydrogen release. Natural−organic silk fibroin provides an approach to fabricate a protective coating on biomedical Mg−Zn−Ca alloy, however, the adhesion force and mechanical properties of the coating on substrates are ought to be further improved without any chemical conversion/intermediate layer. Hereby, based on VUV/O 3 surface activation, a hybrid of silk fibroin and sodium alginate is proposed to enhance the adhesion force and mechanical properties of the composite coatings on hydrophilic Mg−Zn−Ca alloy surfaces. Various mass ratios of sodium alginate addition were investigated to achieve the optimum coating strategy. The nanoscratch test and nanoindentation test confirmed that the adhesion force was tripled and mechanical properties index was significantly improved when the mass ratio of silk fibroin/sodium alginate was 70/30 compared to pure silk fibroin or sodium alginate coatings. Meanwhile, the corrosion rate of the coated Mg−Zn−Ca alloy was significantly delayed with the addition of sodium alginate, resulting in a reaction layer during corrosion process. Furthermore, the mechanisms for both adhesion and corrosion processes were discussed in detail. Our findings offer more possibilities for the controllable surface performance of degradable metals.

A robust network binder via localized linking by small molecules for high-areal-capacity silicon anodes in lithium-ion batteries

Silicon is known for high-capacity yet large-volume-change properties when used as lithium storage material. Polymeric binders substantially contribute to improving the cycling life and increasing areal capacity of silicon anode. Herein, a robust network binder (PG-c-ECH) via localized linking by small molecules is proposed to achieve stable cycling performance of silicon anode with high areal capacity. Peach gum (PG) is rich in abundant hydroxyl and carboxyl groups that conventionally ensure a strong binding affinity between the PG and Si. The epichlorohydrin (ECH) introduced as the short-chain chemical crosslinker further enhances the localized linking for the polymer chains. The resultant PG-c-ECH owns durable interfacial adhesion and outstanding mechanical properties to stabilize the structural integrity of Si anode. Herein, a robust network binder (PG-c-ECH) via localized linking by small molecules is proposed for high-areal-capacity Si anode. Because of its strong interfacial adhesion and excellent mechanical properties, the PG-c-ECH binder could tolerate the huge volume changes of Si active materials during repeated cycling. The Si electrodes using PG-c-ECH as the binder exhibit stable cycling performances at practical-level areal capacities. • A robust network binder (PG-c-ECH) via localized linking by small molecules is proposed. • The Si@PG-c-ECH electrode can be cycled over 10 mAh cm −2 for 35 cycles. • The Si@PG-c-ECH electrode achieves an ultrahigh discharge areal capacity of 60.00 mAh cm −2 . • The full-cell using the Si@PG-c-ECH anode shows a relatively stable cycling performance.

Microstructure and properties of monolayer, bilayer and multilayer Ta2O5-based coatings on biomedical Ti-6Al-4V alloy by magnetron sputtering

In recent years, tantalum pentoxide (Ta2O5) ceramic coating has attracted considerable attention in the modification of implants due to its excellent biocompatibility, high corrosion resistance, and good wear resistance. However, the poor adhesion to the substrate degrades its performance and may become a significant obstacle to its clinical application. In the paper, Ta2O5 monolayer, Ta2O5/Ti bilayer, and Ta2O5/Ta2O5-Ti/Ti multilayer coatings were prepared on the Ti-6Al-4V alloy by magnetron sputtering. The microstructure, chemical composition, residual thermal stress, adhesion strength, mechanical properties, tribological behaviors, and corrosion resistance of the coatings were investigated and compared. The results showed that these deposited coatings were composed of an amorphous nano-Ta2O5 phase, and their surfaces were smooth, dense, and homogeneous without any cracks. Ta2O5/Ta2O5-Ti/Ti coatings exhibited lower thermal residual stress than that of the Ta2O5 and Ta2O5/Ti coatings, which could be attributed to the decrease of the coefficient of thermal expansion (CTE) mismatch between the Ta2O5 film and Ti-6Al-4V substrate due to the introduction of the Ta2O5-Ti/Ti double-interlayer. Moreover, Ta2O5/Ta2O5-Ti/Ti coating was significantly superior to Ta2O5 and Ta2O5/Ti coatings in the adhesion strength, mechanical properties, and wear resistance. These Ta2O5-based coatings can provide excellent corrosion protection for Ti-6Al-4V alloy in simulated body fluids (SBF). The Ta2O5 monolayer coating samples showed the best corrosion resistance, mainly due to its thick out-layer Ta2O5 film. These experimental results provide a feasible way to improve the performances of Ta2O5 coating on Ti-6Al-4V alloy.

Identifying best parameters of particleboard bonded with dextrin-based adhesives

Abstract The objective of this study was to evaluate the best parameters of particleboard manufacturing throughout the physical and mechanical properties’ test under Japanese Industrial Standard. Particleboard panels were manufactured from veneer waste of sengon wood (Paraserianthes moluccana) bonded with dextrin-based adhesives (DAs) and urea formaldehyde (UF) adhesives at the density target of 0.70 g/cm2 under various manufacturing parameters of adhesives composition, load pressure and pressure temperatures. The results showed that an increase in the value of physical and mechanical properties occurred on particleboards which were glued with DAs added with UF. As the addition of UF adhesive increases, the physical and mechanical properties of the particleboard also gradually increase. This confirms that a good bonding occurs when adding UF adhesives compared to using only dextrin. The particleboard manufacturing parameters demonstrated the best properties when 40% DA was mixed with 60% UF adhesives (DA–UF = 40:60 pbw; P12) for the physical test and 20% DA mixed with 80% UF (DA–UF = 20:80; P13) for the mechanical test for both particleboards under the load pressurized at 40 kgf/cm2 for 30 min at a temperature of 105°C.

Novel Dual-Curing Process for a Stereolithographically Printed Part Triggers a Remarkably Improved Interlayer Adhesion and Excellent Mechanical Properties.

Stereolithography (SL) is widely used because of its numerous advantages over other three-dimensional printing (3DP) techniques. However, SL is a layer-by-layer process, where interlayer adhesion between adjacent layers becomes more brittle than the intralayer adhesion, common to all 3DP process. Here, we report a facile method to strengthen the interlayer adhesion for SL. By the addition of monomers with thermally curable functional groups (epoxy or hydroxyl groups), thermal post-curing induces chemical reactions between them in adjacent layers after the photoinitiated printing process. It leads to fully 3D cured objects with enhanced interlayer bonding and substantially improved mechanical properties, but not a significant change in the dimensional stability. This approach can expand the use of 3DP techniques in load-bearing applications that require mechanically robust printed objects with precise dimensions.

Synthesis and characterization of thermosensitive hydrogel based on quaternized chitosan for intranasal delivery of insulin.

Nasal administration is a form of systemic administration in which drugs are insufflated through the nasal cavity. Steroids, nicotine replacement, antimigraine drugs, and peptide drugs are examples of the available systematically active drugs as nasal sprays. For diabetic patients who need to use insulin daily, the nasal pathway can be used as an alternative to subcutaneous injection. In this regard, intranasal insulin delivery as a user-friendly and systemic administration has recently attracted more attention. In this study, a novel formulation consists of chitosan, chitosan quaternary ammonium salt (HTCC), and gelatin (Gel) was proposed and examined as a feasible carrier for intranasal insulin administration. First, the optimization of the chitosan-HTCC hydrogel combination has done. Afterward, Gel with various amounts blended with the chitosan-HTCC optimized samples. In the next step, swelling rate, gelation time, degradation, adhesion, and other mechanical, chemical, and biological properties of the hydrogels were studied. Finally, insulin in clinical formulation and dosage was blended with optimized thermosensitive hydrogel and the release procedure of insulin was studied with electrochemiluminescence technique. The optimal formulation (consisted of 2wt% chitosan, 1wt% HTCC, and 0.5wt% Gel) showed low gelation time, uniform pore structure, and the desirable swelling rate, which were resulted in the adequate encapsulation and prolonged release of insulin in 24H. The optimal samples released 65% of the total amount of insulin in the first 24H, which is favorable for this study.

Morphological and microstructural investigation of the non-planar interface formed in solid-state metal additive manufacturing by additive friction stir deposition

Additive friction stir deposition (AFSD) is an emerging solid-state metal additive manufacturing technology renowned for strong interface adhesion and isotropic mechanical properties. This is postulated to result from the material flow phenomena near the interface, but experimental corroboration has remained absent. Here, we seek to understand the interface formed in AFSD via morphological and microstructural investigation, wherein the non-planar interfacial morphology is characterized on the track-scale (centimeter scale) using X-ray computed tomography and the material deformation history is explored by microstructure mapping at the interfacial regions. X-ray computed tomography reveals unique 3D features at the interface with significant macroscopic material mixing. In the out-of-plane direction, the deposited material inserts below the initial substrate surface in the feed-rod zone, while the substrate surface surges upwards in the tool protrusion-affected zone. Complex 3D structures like fins and serrations form on the advancing side, leading to structural interlocking; on the retreating side, the interface manifests as a smooth sloped surface. Microstructure mapping reveals a uniform thermomechanical history for the deposited material, which develops a homogeneous, almost fully recrystallized microstructure. The substrate surface develops partially recrystallized microstructures that are location-dependent; more intra-granular orientation gradients are found in the regions further away from the centerline of the deposition track. From these observations, we discuss the mechanisms for interfacial material flow and interface morphology formation during AFSD.