فهرست مطالب

نشریه فرآیندهای نوین در مهندسی مواد
پیاپی 12 (بهار 1389)

تاریخ انتشار: 1389/04/25
تعداد عناوین: 10

فارسی
English

انتخاب همه

Production of Titanium Carbide and TiC-Al2O3 Nanocomposit Using Rutile by the Use of Combustion Synthesis and Mechanical Alloying Methods

Abdolah Hajalilo, Ali Saeedi, Mehrdad Abbasi Page 1

In this research, titanium carbide and TiC-Al2O3nanocomposite was produced by MASHS method from rutile as a inexpensive material, Aluminum and graphite. Phase analysis of the products was carried out using XRD and microstructure of the product was also studied by SEM. Primary mixture was milled in a planetary ball mill at 8h, 10h, 20h and 60h milling time. The XRD analyses showed that after10h, peaks corresponding to TiC and Al2O3 phase appeared on XRD patterns. The crystallite sizes of TiC and Al2O3 were determined by Williamson-Hall method.. Whit increasing the milling time to 20h peaks corresponding to TiC broadened slightly and diminished in intensity, which are the results of the fineness of the crystallites. The crystallites size was on the scale of nanometer. For samples 20h milled, TiC-Al2O3nanocomposite was heat treated at 8000C and 1200 0C.

Abstract View Paper Original: Persian
Effect of VAR Process on Mechanical Properties, Gas Atoms and Inclusions Content of 18Ni-9Co-5Mo Alloy Produced by VIM Technique

Seyedreza Elmihoseini, Hossein Arabi Page 11

Maraging Steels are a group of steels having high strength and toughness. Presence of inclusions in these steels are harmful for their strength and toughness. Also, there are some active elements within these steels. Therefore, application of advanced melting, refining and casting processes such as vacuum processes are used greatly in production of maraging steels. In this research two C300 maraging steel with 0.65 and 1 wt% Ti were casted firstly in VIM furnace. Then samples subjected to VAR process in order to study the effects of this process on mechanical proerties, inclusions content and gas atoms within the steel. The results show that during VAR process of the bars casted in VIM furnace, the total N and O gases reduced up to 14%, ductility and resistane to impact increased up to 30% and 47% respectively. Comparison of these two steels that produced by VIM+VAR showed that titanium increasing from 0.65 to 1 wt% causes marginal increasing in strength and hardness and marginal decreasing in ductility and resistance to impact of steel.

Abstract View Paper Original: Persian
Study and Comparison of Microstructure, Hardness and Wear Resistance of Hardface Composite Clad Layers (TiC, TiCN) on Mild Steel Fabricated by FCAW

Mehdi Mohammadikhah, Hamed Sabet, Ali Shokouhfar, Saeed Mehrabian, Akbar Hadizadeh Page 21

In this research, metal cored wire including ferroalloy materials was used and cladded by FCAW process with different shielding gases (as nitrogen and argon) on steel substrate. The chemical analysis examination showed that the nitrogen absorbed in sample that was fabricated with nitrogen gas shielding. Consequence of XRD pattern indicated that the Carbonitride phase (TiCN) precipitations appeared in weld metal (nitrogen gas) and titanium carbides (TiC) precipitate in (argon gas) samples. SEM examination results, revealed that the fine particles of TiCN and TiC precipitations sited in ferrite microstructure and the mapping of elements explained the homogeneously precipitates of elements and phases in microstructure. Also, the hardness value sample that fabricated with argon gas was lower than the sample that fabricated with nitrogen gas. The wear test (ASTM G65) result indicated that sample was being consist of TiCN had higher abrasive wear resistance than the other (TiC).

Abstract View Paper Original: Persian
The Effect Of Foam Density and Coating Thickness on The Flow Pattern and Some Parameteres in Lost Foam Casting

Mohammad Khodae, Naser Varharam Page 33

In lost foam casting, pattern and gating system prepared form gasifiable pattern (mainly polystyrene) and coated pattern embedded in unbounded sand. Pattern thermal degraded and under go out from the mold while the molten metal enter the mold. In steel lost foam casting, molten metal has high temperature then foam pattern decompose mainly to the gaseous products and escape from the mold. Back pressure of the decomposed products changes the flow pattern in the mold. In aluminum lost foam casting less heat reaches to the foam pattern and less decomposition occurred and decomposed products mainly in liquid form escape the mold. In this research flow pattern and gas gap length in aluminum and steel lost foam casting investigated using photography technique. Pressure measurement results indicate that back pressure increased with coating thickness, foam density and spure height increscent. Comparison between photography results of aluminum and steel indicate that with increasing metal temperature from aluminum to steel temperature, reaction intensity and the gaseous products volume increased.

Abstract View Paper Original: Persian
Combustion synthesis and mechanochemical synthesis of chromium carbide (Cr3C2)

Abolfazl Amirkavoe, Ali Saeedi Page 47

In this investigation, combustion synthesis and the mechanochemical synthesis of chromium carbide (Cr3C2) were studied using chromium oxide, aluminium and carbon powders. XRD technique was used to characterize the product. Without any mechanical activation, ignition of the raw mixture only resulted in aluminothermic reduction of chromites. When the raw powders were mechanically activated for 2 hours, combustion reactions were completed and Cr3C2 was produced. Results of the mechanochemical process indicated that the aluminothermic reduction of chromites proceed with time and is almost completed after 5 hours. Further milling results in dissolution of carbon in chromium and after 7 hours of milling, distinguished peaks for Cr3C2 appeared in XRD results. No peaks for alumina, a by product of the process, were observed in the XRD pattern which means this phase is amorphous. This was confirmed by annealing of the sample at 1100?C for 1 hr which resulted in a sharp peak for alumina in addition to chromium carbide.

Abstract View Paper Original: Persian
A Comparison Between in Situ-Provided Alumina-Spinel Composites by Gelcasting Using Magnesium Hydroxide and Acetate

Mohsen Haji, Masoud Alizadeh, Mohammad Hassan Amin Page 57

In the present work, in situ production of Alumina-Spinel composite by gelcasting method is investigated. For this purpose, two different raw materials, magnesium hydroxide and magnesium acetate, were used and their properties were studied separately. The results of the sedimentation test show that the amount of dispersant agent in the suspension containing magnesium acetate was smaller than the suspension containing magnesium hydroxide. Also, the segments produced by magnesium hydroxide had higher mechanical properties than the ones produced by magnesium acetate. The effect of sintering time on the spinel phase constitution is examined by XRD. Finally, the existence of further porosities in the segments containing magnesium acetate was proven by SEM.

Abstract View Paper Original: Persian

علمی مصوب

نشریه فرآیندهای نوین در مهندسی مواد

Advanced Prosesses in Materials Engineering

فصلنامه فنی مهندسی به زبان فارسی و انگلیسی

آخرین شماره | آرشیو

ISSN: 2423-3226 eISSN: 2423-3234

صاحب امتیاز:

دانشگاه آزاد اسلامی واحد خمینی شهر

مدیر مسئول:

دکتر کامران امینی

سردبیر:

دکتر علی شکوه فر

تلفن نشریه: ۰۳۱-۳۶۰۲۲۳۳۸

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فهرست مطالب

نشریه فرآیندهای نوین در مهندسی مواد پیاپی 12 (بهار 1389)

نشریه فرآیندهای نوین در مهندسی مواد

Advanced Prosesses in Materials Engineering

نشریه فرآیندهای نوین در مهندسی مواد
پیاپی 12 (بهار 1389)