Titanium Chips Research Articles

Flux Filling Rate Effect on Weld Bead Deposition of Recycled Titanium Chip Tubular Wire

Flux Filling Rate Effect on Weld Bead Deposition of Recycled Titanium Chip Tubular Wire

Synthesize and characterization of silver coated Ti powders from waste titanium chips by mechanical milling assisted electroless plating method

This study used an electroless silver (Ag) coating method on Ti powders obtained from waste turnings using mechanical milling, a recycling technique. Various parameters of Ag source and reducing agent ratios were utilized in the Ag coating processes. The results demonstrated that increasing the silver source and reducing agent ratios resulted in a more homogeneous and thicker Ag coating layer on Ti powders. The rise in the reduced silver ratio resulted in an increase in crystallite size compared to untreated particles, which was attributed to the reduction of residual dislocations in Ti through the presence of Ag. The amount of silver on silver-coated Ti powders ranged from 12.49 wt% to 24.4 wt%. Furthermore, an increase in the silver ratio significantly enhanced the oxidation resistance properties. The mass change with oxidation obtained from TGA analysis reduced from 26.31 wt% to 14.88 wt% with increasing silver coating layer on Ti powders.

Study of cell adhesion, osteogenesis, and angiogenesis of a “groove” structure micro-arc oxidation titanium

The use of titanium alloy-based dental implant restorations has gained popularity due to their attractive properties. Current research on the surface modification of titanium materials primarily centers around the surface integration of various metal ions, the incorporation of different drugs, or other materials. By simply adjusting the process parameters of micro-arc oxidation, we were able to form a “groove” structure in titanium chips. Scanning Electron Microscopy (SEM) observations revealed that Bone Marrow Stem Cells (BMSCs) noticeably elongated along the “grooves”. Immunofluorescence results indicated an elevated expression of Osteocalcin (OCN) and CD31 in “groove” structure group. Furthermore, “groove” structure group also amplified the expression of osteogenic genes (Alkaline Phosphatase, ALP; Osteocalcin, OCN) and angiogenic genes (CD31, Vascular Endothelial Growth Factor, VEGF; Angiopoietin-2, ANG2; and Fibroblast Growth Factor, FGF) on the material surface (P < 0.05). This study suggests that the “groove” structure enhances early cell adhesion on the material surface and improves osteogenic and angiogenic differentiation on the titanium surface, thereby providing potential research implications for enhancing the initial stability of implants.

In vitro evaluation of different protective techniques to reduce titanium particle contamination during implantoplasty

ObjectivesOur aim is to study titanium remains in a bone model during standardized implantoplasty under different isolation and protective modalities.Material and methodsForty implants were placed in artificial spongy bone blocks mimicking a horizontal bone loss and implant neck protrusion of 5 mm. Samples were randomly divided into four groups (n = 10), which were treated as follows: rubber dam (A), a dental adhesive paste (B), bone wax (C), and an unprotected positive control (D). Implantoplasty was performed using carbide and diamond burs under strict water cooling and standardized suction. After removal of the respective isolation materials, the bone blocks were thoroughly rinsed with tap water for 3 min and titanium chips were collected using a filter integrated in the model. The filter paper was removed and dissolved in 37% hydrochloric acid for 2 h at 120 °C and the titanium remnants were quantified using atomic absorption spectrometry.ResultsNone of the test groups were able to completely prevent titanium particle contamination. Rubber dam (691 ± 249 µg) and bone wax (516 ± 157 µg) were found to be significantly more protective than the positive control (2313 ± 747 µg) (p < 0.001) with respect to the amount of titanium particles that remained in the bone model after implantoplasty. The adhesive paste group (1863.5 ± 538 µg) was not significantly different from the positive control (p = 0.19).ConclusionsDespite some limitations of the present study, titanium particles resulting from a standardized implantoplasty can be assumed to be significantly reduced when the tissues/bone were protected with rubber dam and bone wax, or a combination, depending on individual accessibility.Clinical relevanceTissue protective measures to reduce or avoid particle contamination during implantoplasty is possible and should be considered and further clinically assessed to avoid iatrogenic inflammatory reactions.

Attachment of Human Osteoblasts on Carbon-Infiltrated Carbon Nanotubes Versus Medical Grade Titanium Alloy

Finding optimal attachment of human bone cells to artificial implants is pertinent research in order to develop functional implants that will last a lifetime for patients. Carbon-infiltrated carbon nanotubes (CICNT) are being researched as a potential implant surface due to their antibacterial properties. However, little research has been done into whether they are a compatible surface for the growth of bone cells. Human fetal osteoblasts (hFOB 1.19) were used as experimental cells to test adaptation on implant surfaces. Medical grade titanium alloy (Ti6Al4V) was tested either as a bare surface or coated with CICNT. A luminescent ATP assay was used to quantify the growth of the bone cells on both materials. A standard curve was developed to correlate the luminescent signal from ATP release to the number of cells present. Data showed that fewer cells were present on both the bare titanium chips and the CICNT chips per unit area than the cells that grew on the plastic well around the chips. Both materials supported a certain level of cell growth, but the titanium chips supported more cells per unit area than the CICNT coated chips. This data provides insight as to the biocompatibility of a CICNT surface coating for medical implants.

Minimally Manipulated Bone Marrow-Derived Cells Can Be Used for Tissue Engineering In Situ and Simultaneous Formation of Personalized Tissue Models

Red bone marrow and autologous bone tissue (bone fragments and bone chips) of the donor were harvested intraoperatively during autoplasty of talus bone defect. Titanium chips were obtained by grinding a fragment of a microporous titanium-coated hip arthroplasty (Zimmer). Bone marrow mononuclear cells were isolated in the operating room, and bone and titanium fragments were incubated with a suspension of mononuclear cells. The quality of revitalization was assessed by fluorescence microscopy and histological examination after culturing of adherent cells on the bone and titanium fragments. During culturing on bone chips, bone marrow mononuclear fraction cells demonstrated significantly higher metabolic activity than bone marrow cells (p=0.04). Mononuclear fraction cells were also capable of stable colonization of titanium fragments with the formation of composite tissue model.

Correction to: Analysis of Densification and Consolidation during the Solid-State Recycling of High Purity Titanium Chips

Correction to: Analysis of Densification and Consolidation during the Solid-State Recycling of High Purity Titanium Chips

Relationship of microstructure and properties of high-purity titanium manufactured by unconventional method of chips recycling

This research concerns the recycling of titanium chips obtained by turning and milling. High-purity (hp) titanium 99.99% wt. was investigated. Four various types of chips were subjected to four separate processes with the aim of transforming the chips into a solid volumetric material. Solid-state processing by heating and plastic working conducted without re-melting was applied. The key operation of the procedure was unconventional direct extrusion with the use of a rotating die. As a result of the experiments, four rods 8 mm in diameter and 500-700 mm long were manufactured. The purpose of this work is to present the microstructure, mechanical properties and machinability of the obtained materials and to show the specific relationship between their microstructure and properties. In the context of microstructure - grains, defects, impurities and porosity were investigated. In turn, the mechanical properties were evaluated by means of hardness, microhardness, tensile and compression tests.It was found that these new manufactured materials were characterized by a proper microstructure (grain size of 8-40 μm, porosity of 0.00–0.28%) and properties similar to that of commercial Ti. For example, the hardness (92-108HV10) and tensile strength (278-367 MPa) of the Ti obtained was in a range proper for the commercial reference titanium 99.99.

The effect of different cleaning methods for titanium chips on the carbon content of ferrotitanium after remelting

Titanium is an important structural metal. Titanium alloy have the characteristics of low density, high strength, good corrosion resistance, good biocompatibility and strong surface decoration, which are widely used in aerospace, medical, construction, sporting goods and other fields. However, titanium alloys are difficult to process, and a large amount of titanium chips stained with oils such as cutting fluid will be produced. Since the high-titanium ferrotitanium used to produce high grade steel requires low carbon content, titanium chips cannot be directly used for remelting and need to be pre-cleaned. In order to obtain the best cleaning conditions of titanium chips, the effects of ultrasonic cleaning of titanium chips with different cleaning agents, different temperatures and different times were investigated in this study. It was determined that the oil removal rate could reach 83.5% by using 5% sodium carbonate solution at 50 °C, 40 kHz ultrasonic cleaning for 20 min. In addition, the cleaning mechanism was analyzed, and the influence modes of slight vibration, saponification and emulsification reaction, and cavitation in ultrasonic cleaning were explained according to Young equation. This paper has positive significance for promoting the production of low-carbon, high-purity and high-titanium ferrotitanium from titanium chips and realizing the secondary recycling of resources.

Analysis of Densification and Consolidation during the Solid-State Recycling of High Purity Titanium Chips

Analysis of Densification and Consolidation during the Solid-State Recycling of High Purity Titanium Chips

Deformation and Microstructure of Titanium Chips and Workpiece

Abstract In order to improve the machinability of titanium alloys, a better understanding of the chip formation process is needed. Microstructur alanalysis of chips produced at high cutting speeds can lead to an estimate of temperatures and the deformation state in the chips if structural changes can be observed. Two-dimensional cross-sectional analyses are performed by means of optical microscopy (LM) and transmission electron microscopy (TEM). To study the deformation state of the finished workpiece, a scratch-grid method in combination with a scanning electron microscope (SEM) is used. The results of the different analyses for Ti 6A14V are presented in this paper and are compared with a finite element simulation of an orthogonal cutting process.

Improving environmental performances of integrated bladed rotors for aircraft

Aircraft engine manufacturers have been reported to cause great environmental impacts within the aircraft manufacturing industry, with a large contribution stemming from the integrated bladed rotors due to special manufacturing requirements. Here we assess all relevant life cycle environmental impacts of manufacturing a Ti–6Al–4 V alloy rotor and investigate potential impact reductions resulting from different recycling scenarios for alloy chips. The hot spot analysis shows a dominance of the material stage compared to manufacturing and hazardous waste disposal. 100% recycling of titanium chips into alloy gives a 52% reduced climate change impact compared to the conventional hazardous waste treatment of the chips.

Effects of laser-textured on rake face in turning PCD tools for Ti6Al4V

The demand inherent to the aeronautical industry in terms of productivity and quality requirements leads to develop new cutting tools. Hence, PCD tools meet the requirements in productivity while machining low machinability aeronautical alloys such as Ti6Al4V. Tool chipbreakers play a considerable role in terms of tool life. However, due to the extreme conditions (temperature and pressure) required to manufacture PCD tools, any complex geometry on tool rake faces is not viable, so chipbreakers are not possible, except for those external to inserts. This work proposes a groove-type laser engraved chipbreaker design and a manufacturing methodology, with experimental validation on turning a Ti6Al4V workpiece. The so-manufactured chipbreakers achieve titanium alloy chip fragmentation, making easy chip removal from the cutting zone. A set of experiments involving various laser parameters to characterize the PCD depth and surface integrity and experimental validation for those chipbreakers designs were carried out in finishing cutting conditions. The optimum parameters for the engraving of PCD were found, obtaining satisfactory breakage of titanium chips. Chip length was always below 17.29 mm.

Solid state processing of titanium chips by an unconventional plastic working

Abstract The aim of this paper is to demonstrate how various titanium chips can be processed into solid bulk materials in the form of rods. In this work, an alternative technology for recycling chips without re-melting is presented. In order to transform chips into a new material, an unconventional plastic working method was applied that involved upsetting, heating and extrusion with a rotating die. Two purities of pure titanium were investigated: Ti Grade4 (the lowest possible purity) and high-purity Ti 99.99 (the highest possible purity). For each of these materials, four geometries of chips were processed, i.e. chips after turning (thin and coarse) and chips after milling (thin and coarse). In this paper, the influence of chip purity and chip geometry on the course and effects of the processing were investigated. In addition, technological aspects such as extrusion force and die wear were analyzed. Independent of the type of chips, the results obtained have proved the efficiency and utility of the applied method. As a result of this processing, solid, bulk products in the form of rods O8 mm in diameter were successfully obtained. The rods were nearly fully consolidated, and their density was practically the same as the density of commercial titanium. The materials obtained exhibited conventional, grained structures. It was also shown that the materials obtained were free from significant structural defects such as porosity and impurities. Additional confirmation of their proper structure and purity was provided by the correct results of hardness (~200 HV10, Ti Gr4, and, ~100 HV10, Ti hp).

The impact of tool point angle and interlayer gap width on interface borehole quality in drilling CFRP/titanium stacks

Although substantial research work has been conducted in order to understand and improve the drilling of multi-material aerospace stacks, some key aspects related to process and tool parameters and their impact on the interface quality still need to be addressed. This paper reports on the research conducted to investigate the impact of tool point angle and interlayer gap width on borehole quality, focussing on the interface region. A number of drilling tests were carried out using tools with different point angles and CFRP/titanium stacks with different interlayer gap widths. The results show that the damage on the CFRP interlayer surface is caused by the drilling of the titanium layer, as some of the upwards-travelling titanium chips penetrate into the stack interface. An increase in tool point angle results in larger entry burrs on the titanium interlayer surface, which is attributed to the correlation between tool point angle and thrust force and the capability of tools with low point angles to remove damage generated by surface skidding. The introduction of an interlayer gap promotes the ingress of titanium chips into the stack interface, thereby leading to more pronounced interface damage.

Structural Aspects and Characterization of Structure in the Processing of Titanium Grade4 Different Chips

This study presents the structural aspects of the solid-state processing of various titanium chips. The structural characterization of: (1) commercial pure Ti in the as-received state, (2) manufactured chips, and (3) products of the chip processing are presented. Pure single-phase titanium Grade4 (Ti Gr4) was processed which, among all grades of pure titanium, is characterized by the lowest possible purity and the highest possible strength at the same time. Four geometries of chips were processed, i.e., chips after turning (thin and coarse), and chips after milling (thin and coarse). An unconventional plastic working method was applied to transform a dispersed form (chips) into solid, bulk metal in the form of rods without re-melting. The rods with a diameter of Ø8 mm and a length of about 500 mm were manufactured. Based on computer tomography and Archimedes measurements, it was found that the manufactured rods were consolidated and near fully dense. In turn, microscopy investigations proved that conventional, polycrystalline, grained structures were obtained. Only an insignificantly small number of internal defects were revealed, meaning that the obtained rods exhibited a proper structure typical for commercial titanium. Obtained materials, except of small surface inclusions, were fee of impurities. Whereas the results of the compression tests proved that the manufactured rods are characterized by new interatomic bonds, cohesion and plasticity analogous to those of titanium in the as-received state.

Recycled Titanium Chips as Initial Product for the Atomisation Process of Powders for Additive Manufacturing to Increase Resource Efficiency

Recycled Titanium Chips as Initial Product for the Atomisation Process of Powders for Additive Manufacturing to Increase Resource Efficiency

Effects of TiC formation in situ by applying titanium chips and other ingredients as a flux of tubular wire

Possibility of a varied flux formulation, associated with high deposition rates, has been an advantage in welding processes by applying tubular wires, especially metal cored arc welding (MCAW), characterized by metallic powders in the flux. However, the presence of an exclusively metallic flux may not establish optimal welding conditions, requiring the addition of other ingredients in the flux. The present paper investigates the welding of tubular wire with titanium alloy chips as the flux and the effects of additional elements TiO2, CaCO3 and CaF2 on the arc behavior such as stability, transfer mode and weld properties. Microstructure was examined by scanning electron microscopy (SEM), and hardness was evaluated by a Vickers microdurometer. The results indicated that the fluxes promoted a characteristic of mixed transfer by short circuiting and globular while the CaCO3 only promoted characteristics of a globular transfer. Fluxes containing TiO2, generally used as an arc stabilizer, showed high levels of disturbance. Despite varying chemical composition of the tubular wire, X-ray diffraction results and images generated SEM, revealed a microstructure replete of faceted TiC for all conditions. Carbide showed no significant differences in morphology. Electrical signals demonstrated considerable effects in transfer mode for each condition. As a consequence of the effects generated by the flux, the properties of the welds were also significantly affected. Hardness variation was improved from 2 to 5 times comparing to the hardness of steel plate.

Development and characterization of Ti-TiC composites by powder metallurgy route using recycled machined Ti chips

In this work, Ti-TiC composite have been prepared by powder metallurgy technique using recycled titanium chips and graphite powder. From the Ti chips obtained from the machining of Ti bar, at first Ti powder was prepared by ball milling method. Then the prepared Ti powder was mixed with graphite (C) powder at 48:12 (wt.) ratio and compacted at different compaction pressure (400–700 MPa) and subsequently sintered at 1200 °C temperature. The sintered pellets were characterized by X-ray diffraction (XRD) technique, scanning electron microscopy (SEM). The density of the composite pellets was measured by Archimedes principle. The hardness value of the produced TiC-Ti composite was assessed by Vickers micro-indentation method, and the wear behaviour was evaluated by sliding wear test using ball on disc wear tester. The experimental results revealed that by combined ball milling and sintering route Ti-TiC composite can be prepared from the waste Ti chips, and the compaction pressure has a significant effect on the properties of the prepared composite.

Carbides formation in weld metal produced by recycling of titanium machining swarf

Application of titanium alloys for orthodontic implants have increase in last years and it has generated a great amount of titanium chips which are disposed as metal scrap. Titanium carbide has high hardness and can be applied as coating reinforcement against wear. Chips of titanium alloys were processed and used in the fabrication of experimental hardfacing consumables for improving the resistance of wear of mechanical components. Coatings were produced in cast steel specimens using the gas tungsten arc welding process. Microstructure was investigated by means of scanning electron microscopy. Microhardness of the coatings was analyzed by a dynamic ultra-micro hardness tester. The microstructure of the welding metal was composed of circular particles of titanium carbide surrounded by a ferritic matrix. The measures made by electron dispersive spectroscopy showed a variation in titanium amount trough the weld, where larger contents of titanium were found, and the matrix. The crystallographic analyses reinforced the formation of titanium carbides embedded in a ferrite matrix into welding metal.