توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Properties of lightweight geopolymer with waste ashes and palm oil clinker aggregates
اطلاعات انتشار: اولین کنفرانس بین المللی مواد پیشرفته، سال
تعداد صفحات: ۹
In the present work, compressive strength of lightweight inorganic polymers (geopolymers) produced by fine fly ash and rice husk bark ash together with palm oil clinker (POC) aggregates has been investigated. Different specimens made from a mixture of fine fly ash and rice husk bark ash with and without POC were subjected to compressive strength tests at 2, 7 and 28 days of curing. The specimens were oven cured for 36 h at 80 oC and then cured at room temperature until 2, 7 and 28 days. Addition of POC to the geopolymeric mixtures caused reduced strength at all age of curing. However a considerable increase in strength to weight ratio was acquired for the specimen with a high content of fine POC particles at 28 days of curing. Thermogravimetric analysis and Fourier transform infrared spectroscopy both also are in agreement with the obtained results from compressive strength tests. It was shown that increasing the POC content reduced the weight loss during thermogravimetric analysis and hence increases the heat stability<\div>

۲Modeling Ductile to brittle transition temperature of functionally graded steels by ANFIS
اطلاعات انتشار: سومین کنفرانس بین المللی عملیات حرارتی مواد، سال
تعداد صفحات: ۸
In the present paper, a model based on adaptive network–based fuzzy inference systems (ANFIS) for predicting ductile to brittle transition temperature of functionally graded steels in both crack divider and crack arrester configurations has been presented. Functionally graded steels containing graded ferritic and austenitic regions together with bainite and martensite intermediate layers were produced by electroslag remelting. For purpose of building the model, training and testing using experimental results from 140 specimens produced from two basic composites were conducted. The data used for the input data in ANFIS models are arranged in a format of six input parameters that cover the FGS type, the crack tip configuration, the thickness of graded ferritic region, the thickness of graded austenitic region, the distance of the notch from bainite or martensite intermediate layer and temperature. According to these input parameters, in the ANFIS, the ductile to brittle transition temperature of each FGS specimen was predicted. The training and testing results in the ANFIS model have shown a strong potential for predicting the ductile to brittle transition temperature of each FGS specimen<\div>

۳Microstructure and hot deformation behavior of AlMg6 alloy produced by equal–channel angular pressing
اطلاعات انتشار: دومین کنفرانس بین المللی آلومینیوم، سال
تعداد صفحات: ۶
Experimental work carried out to assess the strain rate and temperature affected deformation behavior of equal–channel angular pressed (ECAPed) AlMg6 alloy. Elevated temperature compression test performed at temperatures ranged from 360 to 520 , four strain rate of 0.001, 0.01, 0.1 and 1s–1. The flow stress curves are displayed two kind of different behavior, which, at low temperatures or high strain rates, during the initial stage of deformation there is an increase in the flow stress, whereas, at high temperatures or low strain rates, flow curve decrease continuously from yield point due to occurrence of dynamic recrystallization phenomena. Activation energy of deformation is calculated 185.5 KJmol–1 for the alloy. Steady state strain rate sensitivity (SRS) parameters were calculated for the strain rate ratios of 1 2 (1:10), 2 3 (10\100). The increasing of the m values from 0.1 to 0.4 for the applied strain rate ratios of 2 3 (10\100) and 1 2 (1:10), respectively, is assumed to be the result of changing the deformation mechanism from recovery to recrystallization. The effects of number of passes and strain path have been studied on the mechanical and microstructural characteristics of this alloy.<\div>

۴Lightweight geopolymer properties
نویسنده(ها): ،
اطلاعات انتشار: اولین کنفرانس بین المللی صنعت سیمان، انرژی و محیط زیست، سال
تعداد صفحات: ۹
In the present work, compressive strength of lightweight inorganic polymers (geopolymers) produced by fine fly ash and rice husk bark ash together with palm oil clinker (POC) aggregates has been investigated. Different specimens made from a mixture of fine fly ash and rice husk bark ash with and without POC were subjected to compressive strength tests at 2, 7 and 28 days of curing. The specimens were oven cured for 36 h at 80 oC and then cured at room temperature until 2, 7 and 28 days. Addition of POC to the geopolymeric mixtures caused reduced strength at all age of curing. However a considerable increase in strength to weight ratio was acquired for The geopolymer is an alkali–activated aluminosilicate material with a much smaller CO2 footprint than traditional Portland cement products. It has excellent durability and may exhibit many other useful properties such as high compressive strength, excellent resistance to water permeability, and good thermal stability. Solid waste and by–products containing silica and\or alumina can, therefore, be used as source materials for making geopolymer. It is environmentally friendly and needs moderate energy to produce. It also provides a major and cost–effective solution to many problems where hazardous residue has to be treated and stored under critical environmental conditions [1].The compressive strength of an inorganic polymer depends on both the ratio of Si\Al and the types of the utilized raw material. the specimen with a high content of fine POC particles at 28 days of curing. Thermogravimetric analysis and Fourier transform infrared spectroscopy both also are in agreement with the obtained results from compressive strength tests. It was shown that increasing the POC content reduced the weight loss during thermogravimetric analysis and hence increases the heat stability.<\div>

۵Dynamic and Static Softening Behaviors of Al–6%Mg Alloy during two–stage Hot Compression Deformation
اطلاعات انتشار: سومین کنفرانس بین‌المللی آلومینیوم ایران IIAC2014، سال
تعداد صفحات: ۵
The dynamic and static softening behaviors of Al–6%Mg alloy were studied using interrupted two–stage hot compression test. The tests were performed in the temperature isothermally at 480 oCand strain rates of 0.1 and 0.001s– 1. The interrupted deformations were conducted with delay time varying between 29 to 90 s after achieving a strain of approximately 0.5 in the first stage. The results showed that static softening, at constant strain rate, dose not noticeablyoccur with increase of delay time between the deformation stages. Also it was exhibited that softening rate highly enhanced with decrease of strain rate at constant delay time. Moreover, in delay time, static and meta–dynamic recrystallization was considered as the dominant mechanisms at low and high strain rates respectively<\div>
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