Flow Behaviour of M2 Steel Alloy during Semi Solid Isothermal Rapid Compression

2012 ◽  
Vol 192-193 ◽  
pp. 311-316
Author(s):  
Farzad Hosseini Yekta ◽  
S.A. Sadough ◽  
Vahid Pouyafar ◽  
Amin Jabbari
Keyword(s):  
Flow Stress ◽  
Tool Steel ◽  
Constant Strain Rate ◽  
Special Kind ◽  
Holding Time ◽  
Plastic Behavior ◽  
Steel Alloy ◽  
Rapid Compression ◽  
Ram Speed ◽  
Semi Solid

The key to all semisolid processes is spherical and non-dendritic particles suspended in a liquid matrix. This special kind of microstructure causes the semisolid material to behave like a non-Newtonian fluid dependent on time and shear rate. Semi solid metal processing gives less shrinkage and porosity, non-macro segregation, lower flow stress, good formability and increased die life compared with conventional production methods. Therefore, semi solid processing introduces a good option for massive forming of high temperature alloys. Here, by partial remelting of M2 tool steel alloy under rapid compression test, deformation mechanism of steel alloy and its correlation to rheological properties were investigated. Flow stress for M2 tool steel alloy corresponding to solid fraction above 55% derived at constant strain rate and holding time. In order to investigate the parameter involved in this process, in the second stage of experiments the ram speed and holding time are variable. The analysis of the derived curves shows that the semisolid slurries exhibit a pseudo plastic behavior dependent on stain rate and temperature. The classical power law model used to describe the rheological and thixotropic dependence.

Precipitate coarsening during hot-compression testing of NiAl + 2 at.% Nb

1986 ◽  
Vol 44 ◽  
pp. 598-599
Author(s):  
W. M. Sherman ◽  
K. M. Vedula
Keyword(s):  
High Temperature ◽  
Flow Stress ◽  
Weight Ratio ◽  
Constant Strain Rate ◽  
Hot Compression ◽  
Compression Testing ◽  
Second Phase ◽  
Precipitate Coarsening ◽  
High Temperature Mechanical Properties ◽  
Ordered Intermetallic

The strength to weight ratio and oxidation resistance of NiAl make this ordered intermetallic, with some modifications, an attractive candidate to compete with many superalloys for high temperature applications. Recent studies have shown that the inherent brittleness of many polycrystalline intermetallics can be overcome by micro and macroalloying. It has also been found that the high temperature mechanical properties of NiAl can be enhanced through the addition of Nb by powder metallurgical techniques forming a dispersed second phase through interdiffusion in a polycrystalline matrix. A drop in the flow stress is observed however in a NiAl-2 at.% Nb alloy after 0.2 % strain during constant strain rate hot compression testing at 1025°C. The object of this investigation was to identify the second phase and to determine the cause of the flow stress drop.

Effect of Pouring Temperature and Holding Time at Semi-Solid Region on the Morphology of Primary Solid Phase in Semi-Solid Slurry

2006 ◽  
Vol 510-511 ◽  
pp. 782-785 ◽  
Author(s):  
Suk Won Kang ◽  
Ki Bae Kim ◽  
Dock Young Lee ◽  
Jung-Hwa Mun ◽  
Eui Pak Yoon
Keyword(s):  
Solid Phase ◽  
Holding Time ◽  
Pouring Temperature ◽  
Solid Region ◽  
Semi Solid

Improved wear resistance of P/M tool steel alloy with different vanadium contents after ion nitriding

Wear ◽  
2008 ◽  
Vol 265 (1-2) ◽  
pp. 57-64 ◽  
Author(s):  
R.M. Muñoz Riofano ◽  
L.C. Casteletti ◽  
L.C.F. Canale ◽  
G.E. Totten
Keyword(s):  
Wear Resistance ◽  
Tool Steel ◽  
Steel Alloy ◽  
Ion Nitriding

Investigation into the rapid compression of semi-solid alloy slugs

2001 ◽  
Vol 111 (1-3) ◽  
pp. 31-36 ◽  
Author(s):  
P. Kapranos ◽  
T.Y. Liu ◽  
H.V. Atkinson ◽  
D.H. Kirkwood
Keyword(s):  
Solid Alloy ◽  
Rapid Compression ◽  
Semi Solid

Characterization of Flow Stress for Commercially Pure Titanium Subjected to Electrically-Assisted Deformation

2013 ◽  
Author(s):  
James Magargee ◽  
Fabrice Morestin ◽  
Jian Cao
Keyword(s):  
Flow Stress ◽  
Heating Temperature ◽  
Pure Titanium ◽  
Constitutive Models ◽  
Plastic Behavior ◽  
Commercially Pure Titanium ◽  
Coupled Models ◽  
Commercially Pure ◽  
Electrically Assisted ◽  
Tension And Compression

Uniaxial tension tests were conducted on thin commercially pure titanium sheets subjected to electrically-assisted deformation using a new experimental setup to decouple thermal-mechanical and possible electroplastic behavior. The observed absence of stress reductions for specimens air-cooled to near room temperature motivated the need to reevaluate the role of temperature on modeling the plastic behavior of metals subjected to electrically-assisted deformation, an item that is often overlooked when invoking electroplasticity theory. As a result, two empirical constitutive models, a modified-Hollomon and the Johnson-Cook models of plastic flow stress, were used to predict the magnitude of stress reductions caused by the application of constant DC current and the associated Joule heating temperature increase during electrically-assisted tension experiments. Results show that the thermal-mechanical coupled models can effectively predict the mechanical behavior of commercially pure titanium in electrically-assisted tension and compression experiments.

Simulation the flow of semi-solid steel alloy using an enhanced model

2015 ◽  
Vol 21 (5) ◽  
pp. 913-922 ◽  
Author(s):  
F. Hosseini Yekta ◽  
S. A. Sadough Vanini
Keyword(s):  
Steel Alloy ◽  
Semi Solid

scholarly journals Variasi temperatur pada proses squeeze casting berbahan magnesium semi solid terhadap hasil kekerasan

2021 ◽  
Vol 2 (1) ◽  
pp. 19-26
Author(s):  
Tri Cahyo Wahyudi ◽  
Eko Budiyanto
Keyword(s):  
Squeeze Casting ◽  
Holding Time ◽  
Semi Solid

Pengecoran squeeze merupakan pengecoran yang dimana dalam proses tersebut menggunakan tekanan tinggi dengan cetakan berbentuk die-punch diberikan pada logam cair saat terjadi pemadatan. Pada pengecoran semi solid temperatur tuang sangat berpengaruh pada hasil kekerasan material itu sendiri. Pada proses penelitian yang akan dilakukan, alat squeeze casting dimodifikasi sedemikian rupa dengan penambahan elemen pemananas (coil heater) pada cetakan sehingga proses pengecoran dilakukan di dalam cetakan tersebut. Dengan material Magnesium, tekanan 350 MPa serta variasi temperatur 3500C, 4000C, 4500C dan 5000C untuk lama waktu penekanan 1 menit, dengan holding time 5 menit serta tekanan gas argon 1 bar dan satu sampel  tanpa perlakuan yang bertujuan untuk mengetahui nilai kekerasan bahan serta struktur mikro yang ada pada spesimen tersebut sehingga nantinya hasil dari pengujian ini dapat diaplikasikan sesuai kebutuhan yang diharapkan. Hasil yang diperoleh dari penelitian ini terlihat semakin tinggi temperatur, semakin besar, semakin banyak pula melting pada sampel, terlihat pada temperatur 5000C sehingganya meningkatkan nilai kekerasan sebesar 49,5 HRV, serta berpengaruh pada hasil struktur mikro bandingkan dengan material awal tanpa proses, pada hasil SEM memperlihatkan  pada pembesaraan 1000 kali, Ukuran dari struktur material berubah menjadi lebih homogen seiring naiknya temperatur selama proses squeeze casting.

scholarly journals Impact of Cutting Environments on Sustainable Machining of H13 Tool Steel Alloy

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Vincent A Balogun ◽  
Isuamfon F Edem ◽  
Etimbuk B Bassey
Keyword(s):  
Tool Life ◽  
Tool Steel ◽  
High Speed ◽  
Machining Process ◽  
Steel Alloy ◽  
High Speed Machining ◽  
Sustainable Machining ◽  
H13 Tool Steel ◽  
Green Machining ◽  
The Impact

The use of electrical energy and coolants/lubricants has been widely reported in mechanical machining. However, increased research and process innovation in high speed machining has brought about optimised manufacturing cycle times. This has promoted dry machining and the use of minimum quantity lubrication (MQL). This work understudies the impact of different cutting environments in machining H13 tool steel alloys at transition speed regime with emphasis on sustainable machining of the alloy. To achieve this, end milling tests were performed on AISI H13 steel alloy (192 BHN) on a MIKRON HSM 400 high speed machining centre using milling inserts. After each cutting pass, the milling insert was removed for tool wear measurement on the digital microscope. The electrical power consumed was measured with the Fluke 435 power clamp meter mounted on the three phase cable at the back of the machine. It was discovered that MQL has a promising advantage in terms of tool life with 25 minutes of machining, net power requirement of 10% when compared to dry cutting, and environmental benefits when machining H13 tool steel alloy. This work is fundamentally important in assessing the environmental credentials and resource efficiency regime for green machining of H13 tool steel alloysKeywords— H13 tool steel, green machining, process optimization, tool life, cutting environments, energy consumption 

scholarly journals Multi-pass friction stirred clad welding of dissimilar joined AA6061 aluminium alloy and brass

2018 ◽  
Vol 12 (4) ◽  
pp. 4285-4299
Author(s):  
Nora Osman ◽  
Zainuddin Sajuri ◽  
Mohd Zaidi Omar
Keyword(s):  
Mechanical Properties ◽  
Tool Steel ◽  
Microstructural Analysis ◽  
Welding Process ◽  
Fusion Welding ◽  
Tool Steels ◽  
Aa6061 Aluminium Alloy ◽  
Aisi D2 ◽  
Semi Solid ◽  
Aisi D2 Tool Steel

Tool steels are commonly used to cut metal materials due to their distinctive hardness, resistance to abrasion and deformation. However, tool steels are difficult to be joined using conventional fusion welding process. In this study, a thixotropic property of metal was utilised to butt-join an AISI D2 tool steel by using uncommon direct partial re-melting (DPRM) method. A high frequency of induction heating is used to apply the DPRM method. From the recent study, there are many methods in achieving the globular microstructure with the success of semi-solid joining process. Though, very less information on the microstructural effect of semi-solid joining on the mechanical properties was reported. This study aims to analyse the effect of uniaxial force on the microstructural evolution and mechanical properties of the thixo-joint of D2 tool steel. The microstructural analysis showed the diffusion occurred between the grains of the thixo-joint sample with 2.5 N uniaxial force. The maximum strength of the thixo-joint sample with force was 652 MPa. This was slightly higher than the as-received sample and the thixo-joint sample without force. The average hardness value of the thixo-joint sample was 400 HV due to the transformation of ferrite to the metastable austenite.

Flow Stress and Elongation of Superplastic Deformation in La55Al25Ni20 Metallic Glass

1999 ◽  
Vol 601 ◽  
Author(s):  
Y. Kawamura ◽  
A. Inoue
Keyword(s):  
Flow Stress ◽  
Metallic Glass ◽  
Strain Rate ◽  
Superplastic Deformation ◽  
Constant Strain Rate ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Elongation To Failure ◽  
Crosshead Velocity

AbstractWe have investigated the flow stress and elongation of superplastic deformation in a La55Al25Ni20 (at%) metallic glass that has a wide supercooled liquid region of 72 K before crystallization. The superplasticity that appeared in the supercooled liquid region was generated by the Newtonian viscous flow that exhibits the m value of unity. The elongation to failure was restricted by the transition of the Newtonian flow to non-Newtonian one and the crystallization during deformation. We succeeded in establishing the constitutive formulation of the flow stress in the supercooled liquid region. Its formulation was expressed very well by a stretched exponential function σflow=Dε exp(H*/RT) [1-exp(E/{ε exp(H**/RT)}0.82)]. Formulations describing the elongation to failure in constant-strain-rate and constant-crosshead velocity tests were, moreover, established. It was found from the simulation that the maximum elongation in the constant-strain-rate test reached more than 106% which was two orders of magnitude larger than that in the constant-crosshead-velocity test.

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