NiTi shape memory alloys (SMAs) are extensively used in various significant areas such as aerospace industries, biomedical sector, automobile industries, and robotics field because of their inherent properties, namely, shape memory effect and superelasticity. Nevertheless, the machining of these alloys is a problematic task by conventional machining practices because of various difficulties such as strain hardening, tool failure, high machining time, and poor surface quality. In recent years, researchers have explored various advanced/unconventional machining processes to surmount these challenges and improve the performance characteristics of NiTi SMAs. Wire electrical discharge machining (WEDM) is an effective and reasonable alternative to machine these hard-to-machine alloys among the other available advanced machining processes. A brief overview, characteristics, applications, and conventional machining of NiTi SMAs have been incorporated in this study. This review article provides substantial insight into the various aspects of surface integrity (SI) for NiTi SMAs using WEDM. The current study highlights literature review on the research work accomplished so far in the domain of SI aspects for NiTi-based SMAs, namely, surface characteristics, react layer, phase analysis, elemental composition, micro-hardness, shape recovery ability, and residual stress in WEDM.

Al-based composites with micrometer and submicro-TiB2 reinforcements (1 wt%) have been produced by selective laser melting (SLM) from mixed powder under different processing conditions. The results show that the densification level of SLM-processed composite with submicro-TiB2 particles (>99.0%) was 0.3–2.4% larger than that of micrometer TiB2-reinforced composite under the same processing conditions. The distribution of Si precipitates in the matrix experienced a transform from continuous cellular to directional line-like morphology with reinforcement size decreasing from micron to submicron. The reinforcement size added in the matrix also exhibited a critical influence on preferred orientation and grain size of matrix. The SLM-processed composites exhibited improved tensile strength and ductility with a decrease of reinforcement size. High tensile strength of ∼400 MPa and elongation of ∼3.6% were obtained for the fine TiB2-reinforced samples, increasing by 6 and 13% compared with that of micro-TiB2–added samples, respectively.

In this research, a novel titanium metallic composite, Ti6Al4V powder mixed with 5 at.% Nb powder, was fabricated by selective laser melting (SLM). The effect of Nb addition on their phase transformation, microstructure evolution, mechanical properties, and corrosion behavior were studied. Interestingly, the novel alloy shows a combination of superior plastic deformation (εp= 18.9 ± 1.8%) and high compressive strength (σc= 1593 ± 38 MPa), which is 60.2 and 3.2% higher than that of the SLM-processed Ti6Al4V alloy under optimum printing parameters, respectively. However, the yield strength of Ti6Al4V + 5Nb (973 ± 45 MPa) is lower than that of the Ti6Al4V alloy (1066 ± 12 MPa). The solidification mechanism changes from planar to cellular mode with Nb addition. The ultrafine microstructure β grains are observed, which show a columnar shape and cellular shape. More importantly, the volume fraction of the β phase is significantly increased from 3.7% to 20.4% because of the Nb addition. In addition, the Ti6Al4V + 5Nb alloy possesses better corrosion resistance than the Ti6Al4V alloy. The research highlights that the addition of Nb powder in Ti6Al4V processed by SLM can improve the mechanical properties and corrosion resistance of the material.

The present work is mainly accentuated to improve corrosion resistance performance, adhesion strength, biocompatibility, and cell proliferation of metallic implants. Novel nano triphasic bioceramic composite coating was achieved on 316L SS by the electrophoretic deposition process followed by vacuum sintering. The optimized potential for composite coating on 316L SS was found to be 30 V and 1 min. All the composite coated samples were sintered in a vacuum furnace at various sintering temperature starting from 700 °C to 1000 °C for 1 h. The coated samples were thoroughly characterized in terms of crystallinity, morphology, and surface roughness by XRD, FESEM with EDX, and profilometer studies, respectively. In addition, the coated samples were mechanically characterized using a tap adhesion and Vickers microhardness test. Corrosion performance of the coated sample was characterized by electrochemical studies in Hank's solution. The in vitro cytotoxicity studies for cell viability and cell proliferation was carried out using MC3T3-E1 osteoblast cells. These studies revealed an enhanced cell attachment and proliferation on the composite-coated sample than the uncoated sample, which controlled the discharge of metal ions from the metal surface into the biological system.

Pancreatic cancer is currently one of the most lethal tumors because of delayed diagnosis and treatment. Aminopeptidase N (CD13/APN), expressed in pancreatic cancer cells, is closely related to the malignant biological behavior, for instance, angiogenesis formation, tumor proliferation, and metastasis. In this study, asparagine–glycine–arginine (Asn–Gly–Arg, NGR), selectively binding to CD13 receptor, was modified to construct a novel contrast agent of QDs@Gd3+-NGR for targeted diagnosis and treatment of pancreatic cancer. It consists of QDs-unit for fluorescence imaging, Gd3+-unit for magnetic resonance imaging (MRI), and NGR for binding to CD13 receptor. PANC-1 cells labeled by QDs@Gd3+-NGR showed significant red fluorescence and high intensity on fluorescence and MR imaging, respectively. Besides, it was confirmed that QDs@Gd3+-NGR could inhibit theproliferation, metastasis, and invasion of PANC-1 cells, and increase reactive oxygen species production and death rate in vitro. Reasonably, we believe the targeted contrast agent of QDs@Gd3+-NGR can sensitively detect pancreatic cancer via MR-fluorescence dual-modality imaging, and plays an active role in inhibition of tumor progression. The promising results in this study provide integration of diagnostic and therapeutic strategy for the management of pancreatic cancer in future.

Bioactive dressings which can treat any kind of chronic or acute wounds and can fully replace the conventional gauzes and superabsorbent dressings have proven to be a future market of wound care products in recent times. These dressings are multifunctional, which can effectively combat the wound infection, remove the exudate, promote angiogenesis, and protect the wound from external trauma. Proper selection of bioactive and polymer defines its efficiency. Current research unveils the therapeutic efficacy of curcumin–honey-loaded multilayered polyvinyl alcohol/cellulose acetate electrospun nanofibrous mats as an interactive bioactive wound dressing material. Scanning electron microscopy and Fourier transform infrared spectroscopy analysis infers uniform encapsulation and chemical compatibility of herbal actives and polymer, inside the nanofibrous layers. The as-spun mat shows potential resistance towards Escherichia coli and ∼90% antioxidant activity against diphenyl-picrylhydrazyl (DPPH)–free radical. Additionally, water absorbency, water vapor transmission rate, and wettability analysis show quick and excellent absorption with controlled transmission of wound exudate.

The effects of stress-free and stress-assisted pretreatments at a relatively high temperature on the creep properties of [001] and [011] oriented Ni-based single-crystal superalloys are investigated in this article. The results show that the creep life of the pretreated samples is shorter than that of the original samples. The variation of the γ/γ′ morphology during the creep process is characterized by the microstructure period. Based on the interaction between the dislocations in the γ matrix channel and the γ′ phase, the difference in creep properties of the two oriented alloys after pretreatment is analyzed. Combined with the crystal plasticity theory and the number of activated slip systems observed in the experiments, it can be concluded that the two oriented alloys after pretreatment show obvious creep anisotropy and that the creep life increases with the number of activated slip system.

In this study, precipitate phase transformation behavior, microstructure, and properties of the Cu–1Cr–1Co–0.4Si (wt%) alloy were investigated. Precipitate phase transformation kinetic equations of the alloy under room temperature rolling (RTR) 90% deformation and aging at different temperatures (440–520 °C) were established. The alloy yielded excellent mechanical and electrical properties under RTR 90% deformation and aging at 440 °C for 1 h, and the corresponding hardness, yield strength (YS), ultimate tensile strength (UTS), elongation, and electrical conductivity were 181.6 HV, 573.6 MPa, 653.7 MPa, 7.3%, and 51.6% International Annealed Copper Standard, respectively. The precipitate phase transformation behavior determined the size and volume fraction of the precipitate phase fv, which played a key role in improving the YS. Impurity scattering caused by surplus Si atoms was mainly responsible for decreasing the electrical conductivity. Therefore, these results can provide a reliable theoretical guidance to prepare Cu–Cr–based alloys with high strength and high electrical conductivity.

Hot deformation behavior of a new tailored cobalt-based superalloy for turbine discs was investigated in the temperature range of 1050–1200 °C and the strain rate range of 0.01–10 s−1. The results show that the flow stress is closely related to the deformation temperature and strain rate, and the flow stress curve of the new tailored alloy belongs to a typical dynamic recrystallization (DRX) type. Microstructure observation reveals that the dominant nucleation mechanism of DRX for the new tailored alloy belongs to discontinuous DRX, while continuous DRX only acts as an assistant nucleation mechanism. The optimum processing parameters of hot working are obtained in the temperature range of 1155–1200 °C and the strain rate range of 0.01–0.1 s−1. The activation energy for the new tailored alloy is determined to be 833.0 kJ/mol, and the relationship between grain size and processing parameters is established by appropriate constitutive equations.

The measurement of thin film mechanical properties free from substrate influence remains one of the outstanding challenges in nanomechanics. Here, a technique based on indentation of a supported film with a flat punch whose diameter is many times the initial film thickness is introduced. This geometry generates a state of confined uniaxial strain for material beneath the punch, allowing direct access to intrinsic stress versus strain response. For simple elastic–plastic materials, this enables material parameters such as elastic modulus, bulk modulus, Poisson's ratio, and yield stress to be simultaneously determined from a single loading curve. The phenomenon of confined plastic yield has not been previously observed in thin films or homogeneous materials, which we demonstrate here for 170 -470 nm thick polystyrene (PS), polymethyl-methacrylate (PMMA) and amorphous Selenium films on silicon. As well as performing full elastic -plastic parameter extraction for these materials at room temperature, we used the technique to study the variation of yield stress in PS to temperatures above the nominal glass transition of 100 °C.