Surface Engineering Techniques and Applications

2014 ◽  
pp. 73-101
Author(s):  
Dharam Persaud-Sharma
Keyword(s):  
Surface Engineering ◽  
Weight Ratio ◽  
High Strength ◽  
Orthopedic Implants ◽  
Strength Properties ◽  
Automotive Components ◽  
Hydroxide Film ◽  
Important Challenge ◽  
Cast Magnesium ◽  
Bone Structures

Magnesium and its alloys are a well-explored type of material with a multitude of applications ranging from biomedical prosthetics to non-biological tools such as automotive components. The use of magnesium and its alloys are highly desired for such applications mainly because magnesium is lightweight and possesses a high strength to weight ratio, which reduces the amount of energy required for the operation of an apparatus. In particular, the biomedical industry uses magnesium as orthopedic implants because of its strength properties that are similar to organic bone structures. Additionally, the highly corrosive or degrading nature of magnesium makes it suitable for degradable implants or medical devices. Cast magnesium alloys are also used as components in modern engines and automobiles, as magnesium's lightweight and high strength properties permit for faster automotive speeds, acceleration, and reduced energy consumption. Magnesium produces a quasi-passive hydroxide film that offers little to no inhibition of corrosion processes. Although the degree of film passivity can be increased through metallurgical techniques like alloying, the highly oxidizing nature of magnesium remains the single most important challenge to its widespread use. This chapter provides a detailed explanation of the most successful mechanisms used to control the corrosion of magnesium and its alloys and highlights the benefits and challenges for using them.

scholarly journals Effect of thermal cycling on mechanical and microstructural properties of heat-treated Ti-6Al-4V alloy

2022 ◽  
Author(s):  
Venkata Siva Teja Putti ◽  
S Manikandan ◽  
Kiran Kumar Ayyagari
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Weight Ratio ◽  
High Strength ◽  
Stress Relief ◽  
Strength Properties ◽  
Thermal Cycles ◽  
Β Phase ◽  
Solution Treated ◽  
Heat Treated

Abstract Titanium (Ti-6Al-4V) is an α+β phase-field alloy utilized in many industries due to its high strength-to-weight ratio and near-net shaping capability. Solution treated & aging, and stress relief annealing processes were performed on the samples to increase the strength and % of elongation. The heat-treated samples then thermally cycled for 500 cycles, 1000 cycles, and 1500 cycles to evaluate the microhardness and tensile properties. The presence of martensite and α2 precipitates in the thermally cycled samples was confirmed by scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). In this investigation, at 1000 thermal cycles, all specimens show improvement in both hardness and strength when compared within the cycles. Solution-treated and aging (STA), stress relief annealing (SRA), and without any heat-treatment (WHT) processes have their highest hardness values recorded for 1000 thermal cycles, and the values are 471 HV0.5, 381 HV0.5, and 374.6HV0.5, respectively. For the SRA process, ultimate tensile strength (UTS) of 925 MPa and yield strength (YS) of 896 MPa have resulted in 1000 cycles. Similarly, at 1000 thermal cycle WHT processed samples yielded UTS of 920 MPa and YS of 885 MPa. STA process samples that are heat-treated for 1000 thermal cycles have better strength properties than SRA and WHT and had a UTS of 1530MPa and YS of 1420MPa. From a ductility point of view, a maximum elongation of 29% for the STA process has resulted. Compared to forged titanium alloy (base metal), an increase of 31% elongation and 41% ultimate tensile strength for solution treated and aging process at 1000 cycles has resulted in this investigation.

Analysis of Mechanical Properties on Roselle Fibre with Polymer Matrix Reinforced Composite

2016 ◽  
Vol 16 ◽  
pp. 1-6 ◽  
Author(s):  
S. Nallusamy
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Matrix Composite ◽  
Polymer Matrix ◽  
Weight Ratio ◽  
High Strength ◽  
Strength Properties ◽  
Reinforced Composite ◽  
Composite Field ◽  
Structural Applications

Over the past two decades it has been established that composite materials are the leading emerging materials. The natural fibres present a number of advantages over traditional synthetic fibres because of their better corrosion resistance, excellent thermo-mechanical properties and high strength to weight ratio. Also the composite materials play an important role in maintaining the eco-friendly design requirements. Among this, polymer matrix composite is one of the recent developing sectors on the composite field, because it has high strength with less density as compared to the metal matrix composite. Depending on the applications, the properties of the polymer reinforced composite are improved by modifying compositions, process of fabrication and direction of fibre etc. In this analysis the Roselle Fibre (Hibiscus Sabdariffa) is reinforced with polymer composite by wt % in the mode of compression molding. The mechanical properties of the above fabricated material were analyzed by ASTM Standards and also the characterization of polymer composites were analysed using SEM. The compressive strength and the hardness value were high as compared to other strength properties; hence it is more suitable for compressive and structural applications. The results concluded that the treated fibre with chemical reveals better compatibility with polymer matrix than that of untreated fibre.

scholarly journals Experimental Behavior of Composite Beam using Hot Rolled Channel and Cold Formed Lipped Channel Section under Flexure

2020 ◽  
Vol 9 (5) ◽  
pp. 2174-2179
Keyword(s):  
Experimental Study ◽  
Composite Beam ◽  
Weight Ratio ◽  
High Strength ◽  
Strength Properties ◽  
Flexural Behavior ◽  
Optimized Design ◽  
Design Strength ◽  
Channel Section ◽  
Hot Rolled

Cold formed construction has widely recognized as an important contribution of saving in weight of steel as well as it can be formed according to strength requirements.Cold formed sections may have higher moment of inertia as compare to same weight hot rolled sections. Composite construction is usually associated with hot rolled sections especially I section, double C channel section considering high strength to weight ratio. The traditional hot rolled sections can be replaced by high strength cold formed sections considering its strength properties, less weight, easy fabrication and to fit demands of optimized design. This paper deals with experimental study of flexural behavior of composite beam using hot rolled as well as cold formed steel section. Two composite beams were casted using hot rolled ISMC 100 (back to back with spacing 50 mm) and Cold formed lipped channel section (back to back with spacing 50 mm). Experimental study conducted with simply supported loading conditions under two-point loading. Cold formed lipped channel section is pre- fabricated considering cold formed sectional properties given by EN 1993-1-3. Loading is given with load increment of 50 kN.Values of mid span deflection and slip at interface were recorded. The test strength of composite beam compared with design strength predicted by Eurocode standard.

The Relation between Microstructure and Corrosion Behavior of New Mg-Al-X Alloys for Transportation Application

2010 ◽  
Vol 95 ◽  
pp. 43-46
Author(s):  
Guy Ben-Hamu ◽  
D. Eliezer ◽  
Kwang Seon Shin
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloys ◽  
Automotive Industry ◽  
Corrosion Behaviour ◽  
Weight Ratio ◽  
High Strength ◽  
Die Cast ◽  
Cast Magnesium Alloys ◽  
Cast Magnesium ◽  
Dc Polarization

New die cast magnesium alloys have increasingly been developed in recent years for the automotive industry due to their high potential as structural materials for low density and high strength/weight ratio demands. However, their poor mechanical properties and low corrosion resistance have led to a search for new kinds of magnesium alloys with better strength, ductility, high temperature behaviour and high corrosion resistance. The main objective of this research is to investigate the corrosion behaviour of new die cast magnesium alloys: Mg-Al-Ca, Mg-Al-Sr. AC and DC polarization tests were carried out on the new alloys. Microstructure was examined using optical and electron microscopy (SEM) and EDS. The additions of Sr and Ca affected the corrosion behaviour. These results can be explained by the effects of alloying elements on the microstructure of Mg alloys such as grain size and precipitates caused by the change in precipitation.

Precipitation in Al-Li-Zr alloys

1992 ◽  
Vol 50 (1) ◽  
pp. 186-187
Author(s):  
D.M. Vanderwalker
Keyword(s):  
Fracture Toughness ◽  
Precipitation Hardening ◽  
Weight Ratio ◽  
High Strength ◽  
Transmission Electron ◽  
Water Quench ◽  
Aluminum Lithium ◽  
Aluminum Lithium Alloys ◽  
Lithium Alloys ◽  
Zr Alloys

Aluminum-lithium alloys have a low density and high strength to weight ratio. They are being developed for the aerospace industry.The high strength of Al-Li can be attributed to precipitation hardening. Unfortunately when aged, Al-Li aquires a low ductility and fracture toughness. The precipitate in Al-Li is part of a sequence SSSS → Al3Li → AlLi A description of the phases may be found in reference 1 . This paper is primarily concerned with the Al3Li phase. The addition of Zr to Al-Li is being explored to find the optimum in properties. Zirconium improves fracture toughness and inhibits recrystallization. This study is a comparision between two Al-Li-Zr alloys differing in Zr concentration.Al-2.99Li-0.17Zr(alloy A) and Al-2.99Li-0.67Zr (alloy B) were solutionized for one hour at 500oc followed by a water quench. The specimens were then aged at 150°C for 16 or 40 hours. The foils were punched into 3mm discs. The specimens were electropolished with a 1/3 nitric acid 2/3 methanol solution. The transmission electron microscopy was conducted on the JEM 200CX microscope.

A novel predictive method for filler coflocculation with cellulose microfibrils

TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 653-664
Author(s):  
IGNACIO DE SAN PIO ◽  
KLAS G. JOHANSSON ◽  
PAUL KROCHAK
Keyword(s):  
Negative Impact ◽  
High Strength ◽  
Strength Properties ◽  
Cellulose Microfibrils ◽  
Paper Strength ◽  
Flow Loop ◽  
Cationic Starch ◽  
Reflectance Measurement ◽  
Drainage Rate ◽  
Complete Study

Different strategies aimed at reducing the negative impact of fillers on paper strength have been the objective of many studies during the past few decades. Some new strategies have even been patented or commercialized, yet a complete study on the behavior of the filler flocs and their effect on retention, drainage, and formation has not been found in literature. This type of research on fillers is often limited by difficulties in simulating high levels of shear at laboratory scale similar to those at mill scale. To address this challenge, a combination of techniques was used to compare preflocculation (i.e., filler is flocculated before addition to the pulp) with coflocculation strategies (i.e., filler is mixed with a binder and flocculated before addition to the pulp). The effect on filler and fiber flocs size was studied in a pilot flow loop using focal beam reflectance measurement (FBRM) and image analysis. Flocs obtained with cationic polyacrylamide (CPAM) and bentonite were shown to have similar shear resistance with both strategies, whereas cationic starch (CS) was clearly more advantageous when coflocculation strategy was used. The effect of flocculation strategy on drainage rate, STFI formation, ash retention, and standard strength properties was measured. Coflocculation of filler with CPAM plus bentonite or CS showed promising results and produced sheets with high strength but had a negative impact on wire dewatering, opening a door for further optimization.

TUNGUM ALLOY

Alloy Digest ◽  
2012 ◽  
Vol 61 (5) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Weight Ratio ◽  
High Strength ◽  
Fatigue Properties ◽  
Excellent Corrosion Resistance

Abstract Tungum alloy combines an unusually high strength-to-weight ratio, with ductility, excellent corrosion resistance, and good fatigue properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming. Filing Code: Cu-806. Producer or source: Tungum Ltd.

SANDVIK Ti-3Al-2.5V GRADE 9

Alloy Digest ◽  
1997 ◽  
Vol 46 (9) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Endurance Limit ◽  
Weight Ratio ◽  
High Strength ◽  
Strain Ratio ◽  
Bend Strength ◽  
Aerospace Applications ◽  
Excellent Corrosion Resistance ◽  
Titanium Aluminum ◽  
Fatigue Endurance

Abstract Sandvik Ti-3Al-2.5V Grade 9 titanium-aluminum alloy offers excellent corrosion resistance, especially to chloride media, and has a high strength-to-weight ratio, which is especially suitable for use in aerospace applications. Tubing can be produced having a CSR (contractile strain ratio) that enhances the fatigue endurance limit. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength as well as fatigue. It also includes information on corrosion resistance as well as forming, machining, and joining. Filing Code: TI-109. Producer or source: Sandvik.

DONEGAL DC-50

Alloy Digest ◽  
1954 ◽  
Vol 3 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Precipitation Hardening ◽  
Weight Ratio ◽  
High Strength ◽  
Heat Treating

Abstract Donegal DC-50 is a precipitation hardening stainless steel having high strength-weight ratio. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: SS-17. Producer or source: Donegal Manufacturing Corporation.

Causes of gear pump fails and methods for their elimination

2020 ◽  
pp. 98-107
Author(s):  
Vitaliy A. Zuyevskiy ◽  
Daniil O. Klimyuk ◽  
Ivan A. Shemberev
Keyword(s):  
Adhesion Strength ◽  
Production Systems ◽  
Low Cost ◽  
High Strength ◽  
Strength Properties ◽  
Research Purpose ◽  
Working Fluid ◽  
Gear Pump ◽  
Repair Service ◽  
Recovery Method

Gear pumps are an important element of many production systems and their replacement in case of failure can be quite expensive, so it is important to have a modern and well-tuned technology for their recovery. There are many methods for restoring the pump's performance, depending on the reason that led to its failure. (Research purpose) The research purpose is in determining what causes most often lead to loss of pump performance, and developing a recovery method that provides the greatest post-repair service life of the pump and low cost of repair. (Materials and methods) Authors took into account that the applied coatings must have sufficient adhesion strength and resistance to mechanical, thermal and corrosion loads during operation. It was found that most often significant leaks of the working fluid, leading to failure, occur due to an increase in the gap between the inner surface of the housing and the gears due to active wear of the housing wells. Authors determined that the method of electric spark treatment of worn-out housing wells is best suited to perform the task (a large post-repair resource and low costs). (Results and discussion) It was found by laboratory studies of the adhesion strength of electric spark coatings with various electrodes that the best transfer of the material to the substrate is provided by bronze electrodes BrMKts3-1. It was noted that the coatings applied using the BrMKts3-1 electrode have high strength properties. (Conclusions) Research conducted in the center for collective use "Nano-Center" VIM confirmed the possibility of effective recovery of the gear pump by electric spark treatment.

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