دانلود کتاب،مقاله،جزوه و نرم افزار مهندسی مواد
کلیه منابع مورد نیاز دانشجویان و مهندسین مواد (متالورژی ، سرامیک ، جوش ، خوردگی ، نانو و بایومواد)دانلود کتاب،مقاله،جزوه و نرم افزار مهندسی مواد
کلیه منابع مورد نیاز دانشجویان و مهندسین مواد (متالورژی ، سرامیک ، جوش ، خوردگی ، نانو و بایومواد)تنش‌های پسماند در جوش‌های لب به لب اتصالات لوله غیرمشابه
Effect of the welding heat input on residual stresses in butt-welds of dissimilar pipe joints
اثر ورودی حرارت جوشکاری بر تنش‌های پسماند در جوش‌های لب به لب اتصالات لوله غیرمشابه
ABSTRACT
This study used finite element techniques to analyse the thermo-mechanical behaviour and residual stresses in dissimilar butt-welded pipes. The residual stresses at the surface of some weld specimens were measured experimentally by using the hole-drilling method. The results of the finite element analysis were compared with experimentally measured data to evaluate the accuracy of the finite element modelling. Based on this study, a modelling procedure with reasonable accuracy was developed. The developed finite element modelling was used to study the effects of welding heat input on magnitude and distribution of welding residual stresses in butt-welded pipes made of ferritic and austenitic steels. The hoop and axial residual stresses in dissimilar pipe joints of 8 mm thick for V-groove shape were studied. It is shown that the welding heat input has a significant effect on magnitude and distribution of residual stresses in the stainless steel side of the studied joints.
ساخت پودرهای فلزی توسط الکترولیز
Forming metal powders by electrolysis
ساخت پودرهای فلزی توسط الکترولیز
ABSTRACT
Fossil fuels will eventually be replaced by renewables. Currently, the most feasible and efficient way of utilising renewable energy is to convert it to electricity. In response to this change, fossil energy-based pyrometallurgical processes will inevitably shift to electricity driven processes. This chapter considers the feasibility of direct conversion of mineral to metal powder using a new electrochemical method, the FFC Cambridge process. The discussion will be on the background of electrometallurgy and powder metallurgy, the principles of the new process and its application for metal powder production, and the direct route from oxide precursors to alloyed powders.
انتقال حرارت و رفتارانجماد پوستهای در قالب ریختهگری پیوسته
Heat Transfer and Deformation Behavior of Shell Solidification
in Wide and Thick Slab Continuous Casting Mold
انتقال حرارت و رفتار تغییرشکل انجماد پوستهای در ورق بزرگ و ضخیم قالب ریختهگری پیوسته
ABSTRACT
The shell solidification in continuous casting mold is a rather complex process that is coupled with thermal and mechanical behaviors, which are related to numerous of defects occurring in slabs surface and subsurface during practical continuous casting. Intending to increase the understanding of shell thermal and mechanical behaviors in continuous casting molds to improve the casting process, numerous studies[1-13] have been conducted over the past few decades by numerical simulation. However, among these previous studies, most of the mathematical models neglected the effects of mold flux film on shell heat transfer[1-6,11] or assumed that the mold flux film distribution in shell/mold gap was uniform or changed linearly with the mold height[7-10,12,13]. It is obvious that the assumptions did not conform to the actual case of practical continuous casting that the mold flux film in mold distributes dynamically both along mold height and circumference with the evolutions of shell/mold gap and shell temperature, and affects the shell thermal and mechanical behaviors greatly.
رفتار استحاله سرد شدن پیوسته فولاد خط لولهی X70
Continuous cooling transformation behavior of X70 pipeline steel
رفتار استحاله سرد شدن پیوسته فولاد خط لولهی X70
ABSTRACT
The comprehensive mechanical properties of steel depended on the final microstructure and grain refinement. In order to obtain high performance pipeline steel, composition design and the application of controlled rolling and controlled cooling technology had become a key, especially the latter which had decisive influence on the product’s final texture and comprehensive performance in modern iron and steel material production. Along with the development of the modern rolling equipment as well as the in-depth study of controlled rolling and controlled cooling technology, the application of controlled rolling and controlled cooling technology had become an important means of fully excavating the potential of the material properties based on the existing material chemical compositions and it had got the extensive attention from modern iron and steel materials research field.
مشخصههای ضخامت پوسته در ورق تولید شده به روش ریختهگری مداوم
Characteristics of shell thickness in a slab continuous casting mold
مشخصههای ضخامت پوسته در ورق تولید شده به روش ریختهگری مداوم
ABSTRACT
It is of great importance to form a thick and sufficiently uniform solidifying shell in the mold to prevent breakout in the continuous casting process. Breakout starts to take place at the thinnest point commonly, and therefore, it is significant to investigate the slab thickness distribution in longitudinal and transverse directions to determine this point. Experimental and numerical simulations are the two ways for measurement of shell thickness in the mold. The former such as adding sulfur into the mold [1], disturbs the normal production and obtains some useful data, which cannot characterize the shell thickness profiles thoroughly. On the other hand, several scholars have researched the flow, heat transfer, and solidification in the mold by numerical simulation . However, some profound researches on the characteristics of the shell thickness have been done.
آنالیز اشعه ایکس Ti-Nb-Ta-Zr در آلیاژهای تیتانیوم
In situ X-ray analysis of mechanism of nonlinear
super elastic behavior of Ti–Nb–Ta–Zr system beta-type titanium alloy
for biomedical applications
آنالیز اشعه X در جای مکانیسم رفتار سوپرالاستیک غیر‌خطی سیستم Ti-Nb-Ta-Zr
در آلیاژهای تیتانیوم نوع بتا برای کاربردهای زیست‌پزشکی
ABSTRACT
Ti–XNb–10Ta–5Zr (mass %) alloys based on nominal compositions of Ti–35Nb–10Ta–5Zr, Ti–30Nb–10Ta–5Zr, and Ti–25Nb–10Ta–5Zr were fabricated through powder metallurgy and forging and swaging processes for biomedical applications. The tensile deformation mechanisms of the Ti–25Nb–10Ta–5Zr, Ti–30Nb–10Ta–5Zr, and Ti–35Nb–10Ta–5Zr alloys were investigated in situ by X-ray diffraction analysis under several loading conditions.
Under the loading conditions, the X-ray diffraction peaks of all the specimens shifted to higher angles than those obtained under the unloading conditions. For the Ti–30Nb–10Ta–5Zr alloy, the elastic deformation is considered to progress continuously in a different crystal direction although after the elastic strain reaches elastic limit in the crystal direction where the elastic limit is the smallest, slip deformation occurs in that crystal direction. The elastic modulus of this alloy appears to decrease in terms of strain over the proportional limit. Thus, the elastic deformation behavior of the Ti–30Nb–10Ta–5Zr alloy does not obey Hooke's law.
جهت دانلود رایگان نسخه لاتین این مقاله اینجا کلیک کنید .
مواد الکتروکرومیک
Electrochromic Materials
مواد الکتروکرومیک
ABSTRACT
A set of materials exhibit electrochromic activity when constituted as a thin film structure whose coloration can be changed reversibly by electrical charging and discharging . there are two types of such electrochromic materials . The first type is uncolored when unpowered and changes to a colored state when a voltage is applied and returns to its uncolored state when the voltage is removed . In the second type an opposite voltage is required to be applied for bleaching ( or decoloration ) .The degree of coloration is a direct visual indication of the state of charing present in the material .
مواد ابر رسانا
Superconducting Materials
مواد ابر رسانا
ABSTRACT
The phenomenon of superconductivity came to be known in 1911 by observing that a capillary column of mercury immersed in a liquid helium bath woud show an abrupt reduction in resistance and at 4.2 K it became impossible to measure the low resistance exhibited by the column with the then available measurement techniques . It was concluded that below a critical temperature (Tc) the mercury had passed into a new state . Subsequent studies on superconduction were pursued with tin and lead as candidate materials and it was discovered that a critical current density (Jc) is carried by a superconduction sample before it returns to its normal ( metallic ) state .
مقدمه الزامات مهندسی برای مواد کامپوزیتی صنعت هوافضا
Introduction: engineering
requirements for aerospace
composite materials
مقدمه الزامات مهندسی برای مواد کامپوزیتی صنعت هوافضا
ABSTRACT
Composite materials have gained popularity (despite their generally high cost) in high performance products that need to be lightweight, yet strong enough to take high loads such as aerospace structures (tails, wings and fuselages), boat construction, bicycle frames and racing car bodies. Other uses include storage tanks and fishing rods. Natural composites (wood and fabrics) have found applications in aircraft from the first flight of the Wright Brothers’ Flyer 1, in North Carolina on December 17, 1903, to the plethora of uses now enjoyed by man-made (engineered) composite materials on both military and civil aircraft, in addition to more exotic applications on unmanned aerial vehicles (UAVs), space launchers and satellites. Their adoption as a major contribution to aircraft structures followed on from the discovery of carbon fibre at the Royal Aircraft Establishment at Farnborough, UK, in 1964.
وضعیت صنعت در کنترل آخال ها در طی ریخته گری شمش فولادی
State of the Art in the Control of Inclusions during Steel
Ingot Casting
وضعیت صنعت در کنترل آخال ها در طی ریخته گری شمش فولادی
ABSTRACT
This article extensively reviews published research on inclusions in ingot steel and defects on ingot products, methods to measure and detect inclusions in steel, the causes of exogenous inclusions, and the transport and entrapment of inclusions during fluid flow, segregation, and solidification of steel cast in ingot molds. Exogenous inclusions in ingots originate mainly from reoxidation of the molten steel, slag entrapment, and lining erosion, which are detailed in this article. The measures to prevent the formation of exogenous inclusions and improve their removal are provided, which are very useful for the clean steel production of ingot industries.