scholarly journals Design of Low-Cost and High-Strength Titanium Alloys Using Pseudo-Spinodal Mechanism through Diffusion Couple Technology and CALPHAD

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2910
Author(s):  
Chaoyi Ding ◽  
Chun Liu ◽  
Ligang Zhang ◽  
Di Wu ◽  
Libin Liu

The high cost of development and raw materials have been obstacles to the widespread use of titanium alloys. In the present study, the high-throughput experimental method of diffusion couple combined with CALPHAD calculation was used to design and prepare the low-cost and high-strength Ti-Al-Cr system titanium alloy. The results showed that ultra-fine α phase was obtained in Ti-6Al-10.9Cr alloy designed through the pseudo-spinodal mechanism, and it has a high yield strength of 1437 ± 7 MPa. Furthermore, application of the 3D strength model of Ti-6Al-xCr alloy showed that the strength of the alloy depended on the volume fraction and thickness of the α phase. The large number of α/β interfaces produced by ultra-fine α phase greatly improved the strength of the alloy but limited its ductility. Thus, we have demonstrated that the pseudo-spinodal mechanism combined with high-throughput diffusion couple technology and CALPHAD was an efficient method to design low-cost and high-strength titanium alloys.


2020 ◽  
Vol 4 (1) ◽  
pp. 41-48
Author(s):  
Teodoro Astorga Amatosa ◽  
Michael E. Loretero

Bamboo is a lightweight and high-strength raw materials that encouraged researchers to investigate and explore, especially in the field of biocomposite and declared as one of the green-technology on the environment as fully accountable as eco-products. This research was to assess the technical feasibility of making single-layer experimental Medium-Density Particleboard panels from the bamboo waste of a three-year-old (Dendrocalamus asper). Waste materials were performed to produce composite materials using epoxy resin (C21H25C105) from a natural treatment by soaking with an average of pH 7.6 level of sea-water. Three different types of MDP produced, i.e., bamboo waste strip MDP (SMDP), bamboo waste chips MDP (CMDP) and bamboo waste mixed strip-chips MDP (MMDP) by following the same process. The experimental panels tested for their physical-mechanical properties according to the procedures defined by ASTM D1037-12. Conclusively, even the present study shows properties of MDP with higher and comparable to other composite materials; further research must be given better attention as potential substitute to be used as hardwood materials, especially in the production, design, and construction usage.



Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3798
Author(s):  
Meng Sun ◽  
Dong Li ◽  
Yanhua Guo ◽  
Ying Wang ◽  
Yuecheng Dong ◽  
...  

In order to reduce the cost of titanium alloys, a novel low-cost Ti-3Al-5Mo-4Cr-2Zr-1Fe (Ti-35421) titanium alloy was developed. The influence of heat treatment on the microstructure characteristics and mechanical properties of the new alloy was investigated. The results showed that the microstructure of Ti-35421 alloy consists of a lamina primary α phase and a β phase after the solution treatment at the α + β region. After aging treatment, the secondary α phase precipitates in the β matrix. The precipitation of the secondary α phase is closely related to heat treatment parameters—the volume fraction and size of the secondary α phase increase when increasing the solution temperature or aging time. At the same solution temperature and aging time, the secondary α phase became coarser, and the fraction decreased with increasing aging temperature. When Ti-35421 alloy was solution-treated at the α + β region for 1 h with aging surpassing 8 h, the tensile strength, yield strength, elongation and reduction of the area were achieved in a range of 1172.7–1459.0 MPa, 1135.1–1355.5 MPa, 5.2–11.8%, and 7.5–32.5%, respectively. The novel low-cost Ti-35421 alloy maintains mechanical properties and reduces the cost of materials compared with Ti-3Al-5Mo-5V-4Cr-2Zr (Ti-B19) alloy.



2007 ◽  
Vol 336-338 ◽  
pp. 939-941
Author(s):  
Yong Qiang Meng ◽  
Zhi Min Bai ◽  
Chang Hong Dai ◽  
Bao Bao Zhang

A new method for producing silicon carbide platelets with low cost and high yield was introduced. The silicon carbide platelets were synthesized by powder-heating techniques with carbon black and SiO2 powder as raw materials and CoCl2 as catalyst. The starting mixtures were heated at a temperature in the range of 1800-2000°C for the duration of about 2-4h to produce substantially completely unagglomerated silicon carbide platelets with a thickness of 5-20μm and the average diameter of 50-200μm. Compared to the conventional heating, the powder-heating technique is advantageous of less investment on equipment, easy to manufacture and convenient to operate. Furthermore, it is very suitable for realizing the scaled production because of the lower synthesizing temperature, shorter reaction time and greater output.



2011 ◽  
Vol 55-57 ◽  
pp. 578-581
Author(s):  
Bing Quan He ◽  
Wen Ting Chen ◽  
Yang Zheng

Sintered SiC ceramics with difficulty, and its production process and production are more expensive, lower sintering temperature of SiC ceramics and look for new low-cost production process is the focus of materials research workers. Re-crystallization of SiC components of the raw materials requirements of high purity, can not add sintering aids, sintering temperature up to about 2450°C). In this paper, by improving and optimizing the existing production process, to lower the sintering temperature of the new methods and ideas, the study shows that: β-SiC will be added to the sintered α-SiC slurry, and the best particle size ratio of α: β = 15:1 mixture, at the same time, according to re-crystallization of SiC sintering theory, the fine particles (β-SiC, has played the role of sintering agent) adsorption in the coarse particle (α-SiC, the role of the support skeleton) and can greatly reduce the SiC Sintering temperature (50-100°C), and to improve the purity of α-SiC, the most economical way to prepare a high-density, high oxidation resistance, high impact resistance, high strength, high mechanical properties of recrystallized SiC powder .



2020 ◽  
Vol 30 (10) ◽  
pp. 2681-2696
Author(s):  
Zhen-yu WANG ◽  
Li-bin LIU ◽  
Di WU ◽  
Li-gang ZHANG ◽  
Wan-lin WANG ◽  
...  


1999 ◽  
Vol 40 (11-12) ◽  
pp. 5-10
Author(s):  
D.W. Reeve

In the manufacture of bleached kraft pulp, evolving restrictions for effluent discharges and evolving technology are taking us towards lower and lower discharges of effluent and dissolved pollutants. Conflicting interest between economy and the environment often arise. For successful pulp manufacturing enterprises, we must look to processes which are low cost: low capital cost, low chemical cost, high capacity and high yield; and which produce high quality pulp: high strength, clean, bright, stable and uniform. Economic pressure is currently exceedingly great, as chronic overcapacity has led to low prices, low return on investment and the flight of capital from the free markets in which investors operate. Certainly we must work to achieve minimum impact of pulp mills, but developments in processes and process equipment for pulp manufacture must be economically as well as environmentally sustainable.



2020 ◽  
Vol 321 ◽  
pp. 12019
Author(s):  
M. Bodie ◽  
M. Thomas ◽  
A. Ayub

A key design consideration for material selection in the aerospace industry is weight reduction; with excellent strength to weight ratio, high temperature resistance, and fatigue performance, titanium alloys are extensively used. New titanium alloys continue to enhance performance and broaden the range of applications. Titanium Metals Corporation (TIMET) recently developed TIMETAL® 575 (Ti575), a high strength titanium alloy with superior fatigue performance over Ti-6Al-4V, aimed at aerospace applications where these properties are imperative i.e. aerospace turbine discs and blades. [1] [2] This work intends to advance the understanding of the effect of thermal processing of Ti575, by investigating the effect of primary alpha (αp) volume fraction and cooling rate on tensile and fatigue performance in post forged heat-treated microstructures. Microstructural assessment and mechanical performance were completed and are discussed. Three cooling methods from three solution heat-treat temperatures were investigated in this work. The results from these experiments were compared using optical microscopy, electron backscatter diffraction (EBSD), room temperature tensile and high cycle fatigue (HCF) tests.



Procedia CIRP ◽  
2016 ◽  
Vol 45 ◽  
pp. 219-222 ◽  
Author(s):  
Oliver Hatt ◽  
Henrik Larsson ◽  
Finn Giuliani ◽  
Pete Crawforth ◽  
Bradley Wynne ◽  
...  


2014 ◽  
Vol 910 ◽  
pp. 279-282 ◽  
Author(s):  
Ching Wen Lou ◽  
Ya Lan Hsing ◽  
Wen Hao Hsing ◽  
Jia Horng Lin

Non-woven textile industry in an emerging field, with the process short, high yield, low cost and wide source of raw materials, but also has excellent performance of many functions on, making non-woven over the past half century gained textiles attention and consumers of all ages. The proportion of the world of non-woven fiber material used in the product, 85% in rayon ,and the other 15% in natural fibers, polyester fibers which accounted for the largest proportion of use. The experiment uses a low melting point polyester fiber (LPET) 20%, three-dimensional hollow curly polyester fiber (TPET) and recycled far infrared fiber (REPET) 40% each as the basic conditions change pressing temperature 100 °C-140 °C, in order to observe and compare the effects of temperature on the non-woven fabric, this experiment tests including air permeability, tensile strength testing, infrared testing and SEM, respectively in different hot pressing temperature, each of the non-woven hot pressing temperatures sample go through microscopic to analysis for non-woven with the hot temperatures strong reason to improve or decline with hot temperature of air permeability.



2009 ◽  
Vol 618-619 ◽  
pp. 127-134 ◽  
Author(s):  
Phill Doorbar ◽  
Mark Dixon ◽  
Amit Chatterjee

The aero-engine has provided the major drive for the development of new improved titanium alloys in recent years. This paper covers these developments from the workhorse alloy Titanium 6/4 and it’s higher temperature stable mates through to the more exotic intermetallic materials and on to their reinforcement with ceramics. The use of Ti6/4 alloy is now widespread throughout the aero space industry providing a good combination of strength at moderate temperatures (~300°C) a relatively low density and a wide range of processing options ranging from castings to forgings to powder HIP and diffusion bonding. Alloy development for the aero-engine essentially concentrated on either increasing the temperature capability and creep resistance or increasing the strength at intermediate temperatures. Alloys such as Ti 6242 and IMI 834 were aimed at compressor disc applications with operation up to around 600°C. Improvements resulted from compositional control and thermal processing to optimize the microstructure for creep and fatigue. High strength intermediate temperature capability (~500°C) alloys were also developed (Ti6246) where higher levels of molybdenum balance the alpha strengthening additions. The drive for lighter weight led to the development of titanium intermetallic systems. Alloys such as 45-2-2XD and Alloy 7 have been the subject of much research and manufacturing development over the last 20 years, demonstrating that they are capable of operating at temperatures well above those of conventional titanium. More recently, alloys with higher additions of Nb and Ta have shown improved mechanical properties and offer promise to extend the application of TiAl above 700°C. In parallel with intermetallic developments combining titanium alloys with the extreme high strength of ceramic fibres has proved irresistible and many ways to produce titanium composites have been developed. The majority of application development has focused on Ti6/4 alloy as the matrix although other matrix alloys have been investigated and tested in U.S. engine demonstrators. Recently a combination of Ti-22Al-26Nb disks reinforced with orthorhombic MMC ran for over 100 hours in an engine test. However, none of these niche composite systems has yet made the transition into large volume production and the fibre reinforced Ti6/4 system probably offers the greatest potential for implementation. The main barrier to the take up of both advanced intermetallics and titanium composites is the cost of raw materials and processing. The challenge still exists to produce net shape components and provide weight savings at an acceptable cost. This will be the key to future exploitation.



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