Assessment of Low Cost, Sustainable, Reflective Layers for Optical Mixing

2013 ◽  
Vol 572 ◽  
pp. 62-65 ◽  
Author(s):  
Wil Peels ◽  
Kevin Cheng ◽  
Jonathan Hu ◽  
Joe Jiao ◽  
Ding Jin ◽  
...  

The reflective properties of white solder masks are subject to this investigation. Selected materials were used to fabricate test boards with increasing solder resist thickness, ranging from 1 to 4 layers. Reflectivity and reflectivity loss were measured, and some visual and mechanical properties. Our main conclusion is that high reflective white solder masks appear suitable for optical mixing design-in for lighting systems. The main route seems to be to print a first layer of a white photosensitive solder resist, which will define the component footprint for soldering; followed by multiple layers of a screen printed, thermal curable white resist, with slightly bigger opening, which will give the needed reflectivity and stability. Reflectivity increases with increasing layer thickness from 87-90% for one layer of 20µm to 95% for four layers or 80µm. Reflectivity loss up to 10% is observed in the blue spectrum after heat treatment for 1000hrs at 100°C.

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.


2016 ◽  
Vol 16 (4) ◽  
pp. 95-100 ◽  
Author(s):  
J. Pezda ◽  
A. Jarco

Abstract Very well-known advantages of aluminum alloys, such as low mass, good mechanical properties, corrosion resistance, machining-ability, high recycling potential and low cost are considered as a driving force for their development, i.e. implementation in new applications as early as in stage of structural design, as well as in development of new technological solutions. Mechanical and technological properties of the castings made from the 3xx.x group of alloys depend mainly on correctly performed processes of melting and casting, design of a mould and cast element, and a possible heat treatment. The subject-matter of this paper is elaboration of a diagrams and dependencies between parameters of dispersion hardening (temperatures and times of solutioning and ageing treatments) and mechanical properties obtained after heat treatment of the 356.0 (EN AC AlSi7Mg) alloy, enabling full control of dispersion hardening process to programming and obtaining a certain technological quality of the alloy in terms of its mechanical properties after performed heat treatments. Obtained results of the investigations have enabled obtainment of a dependencies depicting effect of parameters of the solutioning and ageing treatments on the mechanical properties (Rm, A5 and KC impact strength) of the investigated alloy. Spatial diagrams elaborated on the basis of these dependencies enable us to determine tendencies of changes of the mechanical properties of the 356.0 alloy in complete analyzed range of temperature and duration of the solutioning and ageing operations.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Shimaa El-Hadad ◽  
Mervat Ibrahim ◽  
Mohamed Mourad

High-entropy alloys (HEAs) are multiprincipal element alloys with controllable properties. Studying the mechanical properties of these alloys and relating them to their microstructures is of interest. In the current investigation, Fe31Mn28 Ni15Al24.5Tix high-entropy alloys with Ti content (0–3 wt.%) were prepared by casting in an induction furnace. Different heat treatments were applied, and the microstructure and hardness of the cast samples were studied. It was observed that addition of up to 3.0 wt.% Ti significantly increases the hardness of the alloy from 300 to 500 (Hv) by the combined effect of solid solution strengthening and via decreasing lamellar spacing. Heat treatment at 900°C for 10 h enhanced the hardness at lower Ti percentages (0.0–0.8 wt.%) by decreasing the lamellar spacing, while no change was observed at higher Ti content. It was also observed that extending the treatment time to 20 h affected negatively the hardness of the alloy. Concluding, HEAs can achieve high hardness using low-cost principle elements with minor alloying additives compared to the other traditional alloys.


2012 ◽  
Vol 217-219 ◽  
pp. 1225-1229 ◽  
Author(s):  
Huseyin Selcuk Halkaci ◽  
Mevlut Turkoz ◽  
Osman Yiğit

Aluminum alloys have good properties such as high strength-to-weight ratio, corrosion resistance and relatively low cost. Nowadays they are primarily used as wrought and cast in many industries such as automotive, aviation and aerospace because of these properties. Aluminum alloys are classified into two categories as non-heat-treatable and heat-treatable. The mechanical properties of the heat-treatable alloys are improved by solution heat treatment and controlled ageing. While mechanical properties of some heat-treatable alloys, especially 2XXX series, become stable with natural ageing at room temperature within a few days, some of them are unstable and exhibit significant changes in properties even after many years. Heat treatment process of AA 2024 is very sensible and critical and therefore should be carefully performed. In this research, effects of the solution temperature, soaking time, heating rate and quenching delay condition of AA 2024 on the mechanical properties were investigated.


2021 ◽  
Vol 1030 ◽  
pp. 63-70
Author(s):  
Elammaran Jayamani ◽  
Chun Jie Yu ◽  
Hari Prashanth ◽  
Kok Heng Soon

Natural fibers have advantages over that of synthetic fibers such as biodegradability, low densities, and low cost of production. Optimum interfacial bonding is crucial since it determines the mechanical properties of a polymer-based composite materials. Surface treatment needs to be performed prior to the composites fabrication in order to improve the interfacial bonding. Coating application is an environmentally friendly alternative to the conventional methods of fiber treatments. In this research, the mechanical properties such as tensile (37.1 per cent increase), flexural strengths (61.7 per cent increase) and hardness (31.4 per cent less prone to surface indentation) of rice straw reinforced Polylactic acid composite at 10 wt% fiber and 90 wt% polymer after fiber treatments are analyzed through fabrication and testing. The fiber treatments involved are alkali treatment, heating treatment and coating. The results showed observable increase in tensile, flexural strengths and hardness for alkali treatment, heat treatment. However, from coating process, there is only slight increase in all the mechanical tests. These results have inferred that heat treatment has the highest improvement in mechanical properties, followed by alkalization and then comes coating.


2019 ◽  
Vol 285 ◽  
pp. 139-145
Author(s):  
Le Cheng ◽  
Hong Xing Lu ◽  
Qiang Zhu ◽  
Xiang Kai Zhang ◽  
Ai Di Shen ◽  
...  

Semi-solid squeeze casting (SS-SC) is a new processing technology which combines semi-solid processing (SSP) and squeeze casting (SC). In this process, semi-solid slurry fills mold by using its rheological property and solidifies under high pressure. It has several advantages, such as stable filling, small heat impact to the mold, low cost, high density and excellent mechanical properties of castings, which receives more and more attention. The microstructure of castings provided by SS-SC is quite different from that of casting provided by conventional SC in as-cast condition, which leads to differences in the evolution of microstructure and mechanical properties in heat treatment process. In this study, A356.2 aluminum alloys castings were provided by both SS-SC and conventional SC respectively. The evolution of microstructure and mechanical properties of castings during heat treatment was investigated to obtain the best mechanical properties of semi-solid squeeze castings. Keywords:Microstructure, Mechanical properties, Heat treatment, A356 alloy, Semi-Solid Squeeze Casting


2021 ◽  
Vol 2086 (1) ◽  
pp. 012199
Author(s):  
E O Osipova ◽  
O A Markelova ◽  
V A Koshuro ◽  
A A Fomin

Abstract In this article the process of induction-thermal modification of titanium coatings formed by electroplasma spraying was considered. The influence of the inductor current on the temperature of processed samples was experimentally established. The research results showed that thermal treatment of the samples with titanium coatings at a temperature of 750–1200 °C and a duration of 300 s led to an increase in porosity from 56±2 to 61±1 % and in microhardness from 1035–1532 to 1825–1883 HV0,98, the sprayed layer thickness decreased from 320±30 to 114±15 μm as well. A change of nanoscale structural elements shape was also observed.


2020 ◽  
Vol 321 ◽  
pp. 11029
Author(s):  
Yangyang Sun ◽  
Hui Chang ◽  
Zhigang Fang ◽  
Yuecheng Dong ◽  
Zhenhua Dan ◽  
...  

Microstructure evolution and mechanical properties of low cost Ti-2Fe-0.1B alloy under different heat treatment were studied. Results indicated that two kinds of equiaxed microstructures with different characteristics were obtained in conventional and double annealing, and typical lamellar microstructure was obtained in β annealing. Tensile test results shown that as-received rolled alloy possess highest strength and plasticity simultaneously due to fine and entangled microstructure. Uniform equiaxed dimples were observed in microstructure, which revealed ductile fracture morphology. Key words: titanium alloy; microstructure; heat treatment; mechanical properties


2016 ◽  
Vol 850 ◽  
pp. 755-761
Author(s):  
Xue Cheng Gao ◽  
Qiang Song Wang ◽  
Guo Liang Xie ◽  
Dong Mei Liu ◽  
Wei Bin Xie ◽  
...  

Sheets of Cu-24wt.%Ag alloy were prepared through the process of forging, cold rolling and heat treatment to reveal the evolution of microstructures, mechanical properties and electrical conductivity. The experimental results showed that nanomultilayered structure of Cu and Ag phases arranged alternatively was obtained, with numerous nanoscale Ag precipitate-fibers embedded in Cu matrix. The lamellas in longitudinal section became curved gradually and shear bands appeared when the deformation exceeded 90.79%. With the increase of rolling strain, the average layer thickness and spacing decreased progressively and reached to less than 200 nm as the strain surpassed 96%, resulting in rapid enhancement of the hardness. The heat treatment at 250°C markedly improved electrical conductivity of the alloy, with little decline of the hardness. The anisotropy of the alloy reduced with rising temperature. Local spheroidization occurred when the alloy was heat treated at 300°C. Hardening of this Cu-Ag alloy is predominated by Cu/Ag interface in strain stage of 80%~99%, leaning mainly upon layer thickness and spacing.


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