scholarly journals Duplex Aging and Gas Nitriding Process as a Method of Surface Modification of Titanium Alloys for Aircraft Applications

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 100
Author(s):  
Oleksandr Tisov ◽  
Magdalena Łępicka ◽  
Yurii Tsybrii ◽  
Alina Yurchuk ◽  
Myroslav Kindrachuk ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Titanium Alloys ◽  
Mechanical Performance ◽  
Case Depth ◽  
Nitriding Process ◽  
Additional Time ◽  
Wear Process ◽  
Double Phase ◽  
Technological Advantage ◽  
Duplex Aging

This study discusses the effect of a duplex aging + nitriding process on the wear resistance of an aged double-phase titanium alloy, BT22. Nitriding was applied simultaneously with the heat treatment of the alloy, which is advantageous over the conventional heat and surface treatment methods applied to titanium alloys. According to the results, the thickness of the case depth of the nitrided samples was 40–50 μm. Moreover, nitrogen was uniformly dispersed in the substrate, which was indicated by the hardness tests. The average microhardness of the substrate material was 300 HV0.01, while the hardness of the top layer was 1190 HV0.01, which is an almost four-fold increase. The applied duplex treatment substantially affected the wear performance of the tested alloy. For the untreated alloy, the maximum coefficient of friction was 0.8, while in the surface-modified sample, the maximum fluctuations reached 0.6. The abrasive wear process was dominant in the nitrided samples, while delamination and adhesive wear were observed for the untreated specimens. The nitrided alloy exhibited double the wear resistance of the untreated samples. The proposed treatment does not require additional time or energy consumption, providing a substantial technological advantage over conventional methods. Though the alpha case reduces the mechanical performance of titanium, the nitriding of only the component sections intended to withstand friction will have a positive effect.

IMPROVEMENT OF WEAR RESISTANCE OF SHREDDER BLADES USED IN A REFUSE-DERIVED FUEL (RDF) FACILITY BY PLASMA NITRIDING

2019 ◽  
Vol 27 (04) ◽  
pp. 1950131
Author(s):  
HAKAN AYDIN ◽  
FURKAN BOSTANCI
Keyword(s):  
Wear Resistance ◽  
Working Conditions ◽  
Plasma Nitriding ◽  
Surface Hardness ◽  
Service Condition ◽  
Case Depth ◽  
Nitriding Process ◽  
Nitriding Time ◽  
Refuse Derived Fuel ◽  
Hardness Values

Refuse-derived fuel (RDF) is a kind of renewable energy source to produce energy for replacement of fossil fuels. Aggressive working conditions in RDF facilities cause the shredder blades to wear out quickly. So, the purpose of this paper was to study the effect of plasma-nitriding process on wear resistance of shredder blades made of AISI D2 tool steel in the service condition of RDF facility. Shredder blades were commercially available from two different suppliers (A and B suppliers). These hardened shredder blades were plasma-nitrided in the mixed nitrogen and hydrogen atmosphere at a volume ratio of 3:1 at 450∘C for 12, 18 and 24[Formula: see text]h at a total pressure of 250 Pa. Characterisation of plasma-nitrided layers on the shredder blades was carried out by means of microstructure and microhardness measurements. Wear tests of plasma-nitrided shredder blades were performed under actual working conditions in the RDF facility. Wear analysis of these shredder blades was conducted using three-dimensional (3D) optical measuring instrument GOM ATOS II. The compositional difference of the shredder blades provided by A and B suppliers played an important role on the nitrided layer. The case depth of A-blades significantly increased with increasing plasma-nitriding time. However, the case depth of B-blades was fairly lower at the same nitriding time and only slightly increased with increasing plasma-nitriding time. Plasma-nitriding process significantly improved the surface hardness of the shredder blades. Maximum surface hardness values were achieved at nitriding time of 18 h for both blades. In this case, this increase in surface hardness values was above 100%. At nitriding time of 24[Formula: see text]h, the maximum surface hardness of A-blades significantly decreased, whereas this decrease in surface hardness of B-blades was the negligible value. The wear test results showed that plasma-nitriding process significatly decreased the wear of shredder blades; 18 h nitriding for A-blades and 24[Formula: see text]h nitriding for B-blades had better wear-reducing ability in the service condition of RDF facility. In these cases, the decreases in the total volume wear loss for A- and B-blades were 53% and 60%, respectively.

Investigation on the Tool Wear Model and Equivalent Tool Life in End Milling Titanium Alloy Ti6Al4V

2018 ◽  
Author(s):  
Kai Guo ◽  
Bin Yang ◽  
Jie Sun ◽  
Vinothkumar Sivalingam
Keyword(s):  
Tool Wear ◽  
Titanium Alloys ◽  
Tool Life ◽  
End Milling ◽  
Cutting Speed ◽  
Carbide Tool ◽  
Wear Model ◽  
Wear Process ◽  
Coated Carbide Tool ◽  
Coated Carbide

Titanium alloys are widely utilized in aerospace thanks to their excellent combination of high-specific strength, fracture, corrosion resistance characteristics, etc. However, titanium alloys are difficult-to-machine materials. Tool wear is thus of great importance to understand and quantitatively predict tool life. In this study, the wear of coated carbide tool in milling Ti-6Al-4V alloy was assessed by characterization of the worn tool cutting edge. Furthermore, a tool wear model for end milling cutter is established with considering the joint effect of cutting speed and feed rate for characterizing tool wear process and predicting tool wear. Based on the proposed tool wear model equivalent tool life is put forward to evaluate cutting tool life under different cutting conditions. The modelling process of tool wear is given and discussed according to the specific conditions. Experimental work and validation are performed for coated carbide tool milling Ti-6Al-4V alloy.

Microstructural characteristics of SiC-B4C reinforced laser alloying composite coatings

2013 ◽  
Vol 20 (4) ◽  
pp. 307-310
Author(s):  
Li Wei
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Fine Particles ◽  
Composite Coatings ◽  
Substrate Surface ◽  
Laser Alloying ◽  
Wear Process ◽  
High Microhardness ◽  
Deep Plowing ◽  
Coating Matrix

AbstractA hard SiC-B4C reinforced composite coating was fabricated by laser alloying of SiC-B4C+Al-Sn-Mo-Y2O3 mixed powders on a Ti-3Al-2V alloy. Al-Sn-Mo mixed powders were first used in the laser alloying technique to improve the wear resistance of titanium alloys. Proper selection of the laser alloying process parameters allows us to obtain a composite coating with a metallurgical combination with substrate. Under the action of Mo, fine particles with high microhardness were produced in the coating matrix and also hindered the formation of adhesion patches and deep plowing grooves during the sliding wear process, leading to the improvement of wear resistance of a titanium alloy substrate surface.

scholarly journals THE INFLUENCE OF SALT BATH NITRIDING VARIABLES ON HARDNESS LAYER OF AISI 1045 STEEL

2016 ◽  
Vol 22 (3) ◽  
pp. 188
Author(s):  
Elhadj Ghelloudj ◽  
Hamid Djebaili ◽  
Mohamed Tahar Hannachi ◽  
Abdenour Saoudi ◽  
Bilal Daheche
Keyword(s):  
Compound Layer ◽  
Salt Bath ◽  
Case Depth ◽  
Nitriding Process ◽  
Hardness Profile ◽  
Aisi 1045 Steel ◽  
Aisi 1045 ◽  
Layer Increase ◽  
1045 Steel ◽  
Salt Bath Nitriding

<span>The aim of  this paper is to study and analyze the effects of a surface controlled salt bath nitriding on the microhardness of AISI 1045 steel. The nitriding process were implemented in salt bath component at ten different times (from 1 h to 10 h) when temperature was constant at (520ºC). The nitriding process repeated of another specimens at the same times but the temperature was (580ºC).The microstructure of surface layers was investigated by optical microscopy. Hardness profiles were measured with low-load hardness testing to determine the growth of the case depth after nitriding. Microhardness testing was carried out on samples to investigate the hardness profile at the transition from the compound to the diffusion layer. The microhardness of surface of nitrided sample at 520ºC and 580ºC was observed in the range of 318–430 HV0.3 and 329–421 HV0.3, respectively. Experimental results showed that the nitrides ε-Fe2-3(N,C) and γ’-Fe4(N,C) present in the compound layer increase the microhardness. It is found that salt bath nitriding parameters (time and temperature) improves the microhardness. </span>

scholarly journals The Improvement of Wear Characteristics on 316L Stainless Steel by Dual Surface Treatment Method

2019 ◽  
Vol 9 (1) ◽  
pp. 5826-5831
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Surface Treatment ◽  
316L Stainless Steel ◽  
Treatment Method ◽  
Case Depth ◽  
Dual Processes ◽  
Boron Diffusion ◽  
Shot Blasting ◽  
Wear Evaluation

Stainless steel is used widespread in various industries, but it has poor wear resistance. Therefore, this study aims to investigate the wear resistance of enhanced surface of 316L stainless steel by applying the combination of surface treatments that consist of shot blasting followed by paste boronizing. Glass beads with diameter 250 microns and the blasting pressure of 6 bar has been used as the shot material in conducting shot blasting process. Paste boronizing process was conducted at temperature 950°C for 8 hours soaking. Data were collected and analyzed which concentrating on the samples’ microstructure, microhardness and wear evaluation. Shot blasting improves the case depth of boride layers formed after performing paste boronizing by boosting the boron diffusion owing to the grain refinement created by shot blasting. The ultimate combination of shot blasting and paste boronizing parameters enhance the case depth of the smooth and compact boride layers with high boron content. The hardness performance increase 624% compared to untreated 316L stainless steel which also highly improve the wear resistance of the material. In this investigation, these dual processes of surface treatment which are shot blasting and paste boronizing can be applied in fabricating the improved 316L stainless steel for industrial usages.

scholarly journals Exploration of Nano-scale Structural Instabilities in Metastable β Titanium Alloys Using Advanced Electron Microscopy

2020 ◽  
Vol 321 ◽  
pp. 12001
Author(s):  
Yufeng Zheng ◽  
Dong Wang ◽  
Rajarshi Banerjee ◽  
Dipankar Banerjee ◽  
Yunzhi Wang ◽  
...  
Keyword(s):  
Titanium Alloys ◽  
Mechanical Performance ◽  
Advanced Characterization ◽  
Hexagonal Structure ◽  
Experimental Conditions ◽  
Nano Scale ◽  
Ω Phase ◽  
Transformation Mechanisms ◽  
Structural Instabilities ◽  
O Phase

A variety of nano-scale structural instabilities formed in different metastable β titanium alloys have been systematically investigated using advanced characterization techniques. The characteristics of three different types of nano-scale structural instabilities, the transformation mechanisms and pathways involved and the critical experimental conditions to generate such nano-scale phases will be reviewed and summarized, including athermal ω phase with hexagonal structure, O’ phase with orthorhombic structure, and incommensurate modulated nanodomains. The athermal ω phase has been observed in the as-quenched state in Ti-xMo (x=12, 15 and 181), Ti-18Mo-5Al, Ti-20V, Ti-5Fe, Ti-5Al-5Mo-5V-3Cr (Ti-5553) and Ti-24Nb-4Zr-8Sn (Ti-2448). O’ phase has been characterized to co-exist with athermal ω phase in the as-quenched state isomorphous titanium alloys, including Ti-26Zr-2Al (at.%), Ti-18Mo, Ti-18Mo-5Al, Ti-5553 and Ti-2448. Incommensurate modulated nanodomains were found in compositionally graded Ti-xFe alloy when the athermal ω phase is suppressed. These various nano-scale structural instabilities need to be taken into consideration when designing novel metastable β titanium alloys to optimize the mechanical performance by microstructure engineering.

On Enhancing Wear Resistance of Titanium Alloys by Laser Cladded WC-Co Composite Coatings

2021 ◽  
Author(s):  
Chaoping Jiang ◽  
Jun Zhang ◽  
Yongnan Chen ◽  
Zhimin Hou ◽  
Qinyang Zhao ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Titanium Alloys ◽  
Composite Coatings

THE INFLUENCE OF THE COMPOSITION AND SIZE OF THE FRACTIONS OF THE COMPOSITE GRAVEL FILLER WITH AN EPOXY MATRIX ON ITS WEAR

2021 ◽  
Vol 3 (144) ◽  
pp. 100-107
Author(s):  
Aleksandr M. Mikhal’chenkov ◽  
◽  
Anna A. Tyureva ◽  
Ivan A. Borshchevskiy ◽  
Larisa S. Kiseleva
Keyword(s):  
Wear Resistance ◽  
Composite Materials ◽  
Epoxy Matrix ◽  
Protective Coatings ◽  
Research Purpose ◽  
Effective Diameter ◽  
Wear Process ◽  
The Matrix ◽  
Sand And Gravel ◽  
Over Time

The widespread use of polymer-based composite materials made it possible to replace expensive metal alloys, increase the strength indicators of structures and improve tribotechnical properties. Their use as protective coatings for structural elements operating in an abrasive environment has yielded good results in increasing wear resistance, which is especially important for parts of tillage tools. (Research purpose) The research purpose is in studying the influence of the composition and size of the fractions of the composite gravel filler with an epoxy matrix on its wear. (Materials and мethods) The article considers five composite materials with different compositions. The prototypes were hollow cylinders with dimensions that provide the contact area necessary for the passage of all processes of abrasive wear. The abrasive composition consisted of a mixture of sand and gravel with a fraction size of about 30-40 millimeters. (Results and discussion) The changes in the wear over time are directly proportional and this confirms the classical views on the wear process. The experiments was conducted on the installation of authors’ design. (Conclusions) The wear over time for experimental composites is the same and is expressed in a straight- line relationship; the maximum wear resistance is a composite in which gravel particles have a size of 2.25 millimeters with its content in the matrix of about 60 mass parts. At the same time, gravel with an effective diameter of 2.25 millimeters creates optimal conditions for self-organization of the wear process and provides a relatively low value of the friction coefficient.

scholarly journals Optimization of Texture Density Distribution of Carbide Alloy Micro-Textured Ball-End Milling Cutter Based on Stress Field

2020 ◽  
Vol 10 (3) ◽  
pp. 818
Author(s):  
Minli Zheng ◽  
Chunsheng He ◽  
Shucai Yang
Keyword(s):  
Wear Resistance ◽  
Stress Field ◽  
Density Distribution ◽  
Titanium Alloys ◽  
Contact Area ◽  
End Milling ◽  
Variable Density ◽  
Milling Cutter ◽  
Ball End Milling ◽  
Texture Density

The insertion of micro-textures plays a role in reducing friction and increasing wear resistance of the cutters, which also has a certain impact on the stress field of the cutter during milling. Therefore, in order to study the mechanisms of friction reduction and wear resistance of micro-textured cutters in high speed cutting of titanium alloys, the dynamic characteristics of the instantaneous stress field during the machining of titanium alloys with micro-textured cutters were studied by changing the distribution density of the micro-textures on the cutter. First, the micro-texture insertion area of the ball-end milling cutter was theoretically analyzed. Then, variable density micro-textured ball-end milling cutters and non-texture cutters were used to cut titanium alloy, and the mathematical model of milling force and cutter-chip contact area was established. Then, the stress density functions of different micro-texture density cutters and non-texture cutters were established to simulate the stress fields of variable density micro-textured ball-end milling cutters and non-texture cutters. Finally, the genetic algorithm was used to optimize the variable density distribution of micro-textured cutters in which the instantaneous stress field of the cutters was taken as the optimization objective. The optimal solution for the variable density distribution of the micro-textured cutter in the cutter-chip tight contact area was obtained as follows: the texture distribution densities in the first, second, and third areas are second, and third areas are 0.0905, 0.0712, and 0.0493, respectively.

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