Impact Deformation and Fracture Behaviour of Cobalt-Based Haynes 188 Superalloy

نویسنده

  • Chien Kao
چکیده

The impact deformation and fracture behaviour of cobalt-based Haynes 188 superalloy are investigated by means of a split Hopkinson pressure bar. Impact tests are performed at strain rates ranging from 1×103 s-1 to 5×103 s-1 and temperatures between 25°C and 800°C. The experimental results indicate that the flow response and fracture characteristics of cobalt-based Haynes 188 superalloy are significantly dependent on the strain rate and temperature. The flow stress, work hardening rate and strain rate sensitivity all increase with increasing strain rate or decreasing temperature. It is shown that the impact response of the Haynes 188 specimens is adequately described by the Zerilli-Armstrong fcc model. The fracture analysis results indicate that the Haynes 188 specimens fail predominantly as the result of intensive localised shearing. Furthermore, it is shown that the flow localisation effect leads to the formation of adiabatic shear bands. The fracture surfaces of the deformed Haynes 188 specimens are characterised by dimpleand / or cleavage-like structure with knobby features. The knobby features are thought to be the result of a rise in the local temperature to a value greater than the melting point. Keywords—Haynes 188 alloy, impact, strain rate and temperature effect, adiabatic shearing.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Flow Stress Modeling in a γ-γ/ Cobalt Base Superalloy by Using the Hyperbolic Sine Equation and ANN Method

The new class of wrought γ-γ/ Co-base superalloys, which are based on Co-Al-W system,  was developed by conventional hot working routes with a high volume fraction of γ/ precipitates and good mechanical properties. The aim of the present study was to predict the flow stress and hot deformation modeling of a novel γ-γ/ Co-base superalloy. The hot compression test...

متن کامل

Examining of Tool Wear in Cryogenic Machining of Cobalt-Based Haynes 25 Superalloy

Haynes 25 alloy (also known as L-605 alloy) is cobalt based super alloy which has widely applications such as aerospace industry, turbine and furnace parts, power generators and heat exchangers and petroleum refining components due to its excellent characteristics. However, the workability of this alloy is more difficult compared to normal steels or even stainless. In present work, an experimen...

متن کامل

Hot Deformation Behavior of Haynes 25 by the Hot Tensile Test

In the present work, hot tensile behavior of Haynes 25 Co-base alloy was investigated in the temperature range of 950-1200 ˚C and 0.1 s-1. Thermodynamic calculations showed that M23C6 and M6C carbides were stable below 1000 ˚C and above 1050 ˚C, respectively. Stress-strain curves also indicated an unusual trend of strain fracture. It was observed that with increasing temperature from 950 to 105...

متن کامل

Nickel-based Superalloy Layer Deposited on AISI H13 Hot Tool Steel Base Metal Using Explosion Cladding process

An experimental test was carried out to explosively clad solution annealed Inconel 718 superalloy on quench-tempered AISI H13 hot tool steel. A wavy with vortices interface geometry was obtained from this experiment. A gradual change in the wavelength along the direction of welding was observed which was due to a change in the impact angle, following the plate contacts. In this paper, the exper...

متن کامل

Temperature Dependence of Residual Stress in Titanium Nitride Coatings on Haynes 188 Superalloy

Residual stresses in TiN coatings deposited by a reactive ion process on Haynes 188 superalloy, for potential application in jet engines, were determined over the temperature range from 30–800 °C, using high temperature X-ray diffraction. In the as-coated condition the TiN films have a pronounced [111] orientation texture and a compressive room temperature stress of -10.5 GPa. After heating for...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2014