Anisotropy in Multiaxial Creep of Nickel-Based Single-Crystal Superalloy CMSX-2 : Experiments and Identification of Active Slip Systems

Creep and Stress Relaxation Anisotropy of a Single-Crystal Superalloy

investigation of single-user and multi-user detection methods in mc-cdma systems and comparison of their performances

در این پایان نامه به بررسی روش های آشکارسازی در سیستم های mc-cdma می پردازیم. با توجه به ماهیت آشکارسازی در این سیستم ها، تکنیک های آشکارسازی را می توان به دو دسته ی اصلی تقسیم نمود: آشکارسازی سیگنال ارسالی یک کاربر مطلوب بدون در نظر گرفتن اطلاعاتی در مورد سایر کاربران تداخل کننده که از آن ها به عنوان آشکارساز های تک کاربره یاد می شود و همچنین آشکارسازی سیگنال ارسالی همه ی کاربران فعال موجود در...

Preferred growth orientation and microsegregation behaviors of eutectic in a nickel-based single-crystal superalloy

A nickel-based single-crystal superalloy was employed to investigate the preferred growth orientation behavior of the (γ + γ') eutectic and the effect of these orientations on the segregation behavior. A novel solidification model for the eutectic island was proposed. At the beginning of the eutectic island's crystallization, the core directly formed from the liquid by the eutectic reaction, an...

Effect of Thermal History on Microstructural Changes in Aluminized Nickel-Based Single-Crystal Superalloy

The effect of the thermal history on microstructural changes in aluminized and Pt-aluminized Ni-based single-crystal superalloys was investigated. The superalloy substrates were first electropolished to get rid of the residual surface strain. Then, Pt was electrodeposited and vacuum annealing was conducted for some of the substrates, and aluminized and Pt-aluminized specimens were prepared usin...

Intermediate Temperature Creep Deformation in Cmsx-3 Single Crystals

Creep deformation in < 001 > oriented single crystals of CMSX-3 has been studied at temperatures around 850°C at a stress level of 552 MPa. Detailed observations of the evolution of the dislocation structure during creep have been made. TEM stereo pairs show creep deformation in the matrix phase, leaving the 7’ precipitates undeformed. In previously undeformed crystals there is a brief incubati...