Extension of the Derby relation to metals severely deformed to their steady-state ultrafine-grain size

2014 ◽  
Vol 72-73 ◽  
pp. 59-62 ◽  
Author(s):  
A. Pougis ◽  
L.S. Toth ◽  
J.J. Fundenberger ◽  
A. Borbely
Keyword(s):  
Grain Size ◽  
Steady State ◽  
Ultrafine Grain ◽  
Ultrafine Grain Size

The Effects of Free Space in Mould Cavity on Sandglass Extrusion

2005 ◽  
Vol 475-479 ◽  
pp. 2999-3002
Author(s):  
W.L. Lu ◽  
Y. Wang ◽  
Jin Tao Hai
Keyword(s):  
Grain Size ◽  
Free Space ◽  
Large Strain ◽  
Experimental Results ◽  
Experimental Result ◽  
Ultrafine Grain ◽  
Theory Analysis ◽  
Ultrafine Grain Size ◽  
Mould Cavity

Sandglass extrusion is an ultrafine grain size method. Due to the repetitive and multiple extrusions, large strain will be accumulated and ultafine grain size can be obtained. There are some factors that can affect the experimental result of sandglass extrusion. Among these factors, free space in mould cavity is very important, which can affect the forming of the fold during the extrusion. In this paper, the effects of free space in mould cavity on sandglass extrusion have been discussed and theory analysis and experimental results have been reported.

Microstructure and Mechanical Properties Resulting from Cold Rolling of Equal Channel Angular Extruded Commercial Purity Copper

2006 ◽  
Vol 503-504 ◽  
pp. 733-738
Author(s):  
A. Krishnaiah ◽  
Chakkingal Uday ◽  
P. Venugopal
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Cold Rolling ◽  
Equal Channel Angular Extrusion ◽  
Pure Copper ◽  
Ultrafine Grain ◽  
Ultrafine Grain Size ◽  
Ultrafine Grained ◽  
Angular Extrusion ◽  
Initial Processing

Equal channel angular extrusion (ECAE) is a processing method for introducing an ultrafine grain size into a material. In the present study, a two-step severe plastic deformation process was used to produce ultrafine grained copper with significantly enhanced strength. Equal channel angular extrusion was first used to refine the grain size of copper samples. The copper samples were further processed by cold rolling (CR) to a strain of 0.67 (about 50% reduction). This two-step process produced ultrafine grained copper with strengths higher than those of pure copper processed through ECAE only. This paper reports the microstructures and mechanical properties of the copper specimens processed by a combination of room temperature ECAE and CR. The effectiveness of initial processing by ECAE prior to cold rolling is discussed.

The Effect of Process Route on the Mechanical Properties and Microstructure Aluminum Al-Si-Cu-Mg-Mn Alloys

2020 ◽  
Vol 402 ◽  
pp. 67-72
Author(s):  
Rahmawaty ◽  
Surya Dharma ◽  
Abdul Razak ◽  
Sarjianto ◽  
Nisfan Bahri ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Room Temperature ◽  
Solution Treatment ◽  
Hardness Test ◽  
Optical Microscope ◽  
Ultrafine Grain ◽  
Angular Pressing ◽  
Process Route ◽  
Ultrafine Grain Size

Equal-channel angular pressing (ECAP) is an effective fabrication process to modify ultrafine grain size. It is believed that the smaller grain size could improve the mechanical properties. In the present work, the solution treatment applied to Al-Si-Cu-Mg-Mn alloy. Furthermore, two models of ECAP have been done through one-to-three pass at room temperature. The microstructures were observed by optical microscope (OM) and scanning electron microscope (SEM). The micro-hardness of longitudinal plane was analyzed by vickers hardness test. The strength of ECAP materials at room temperature was obtained by using tensile test. The results show that the ECAP process has improved mechanical properties of alloys, which were the hardness and ultimate tensile strength tend to increase since single pass stage.

Low-Temperature Spark Plasma Sintering of Yttria Ceramics with Ultrafine Grain Size

2011 ◽  
Vol 94 (10) ◽  
pp. 3301-3307 ◽  
Author(s):  
Hidehiro Yoshida ◽  
Koji Morita ◽  
Byung-Nam Kim ◽  
Keijiro Hiraga ◽  
Kohei Yamanaka ◽  
...  
Keyword(s):  
Grain Size ◽  
Low Temperature ◽  
Spark Plasma Sintering ◽  
Ultrafine Grain ◽  
Plasma Sintering ◽  
Ultrafine Grain Size ◽  
Spark Plasma

Hall-petch dependence for ultrafine grain size electrodeposited chromium

1985 ◽  
Vol 19 (1) ◽  
pp. 89-91 ◽  
Author(s):  
C.P. Brittain ◽  
R.W. Armstrong ◽  
G.C. Smith
Keyword(s):  
Grain Size ◽  
Ultrafine Grain ◽  
Ultrafine Grain Size

MICROSTRUCTURE AND HARDNESS OF FRICTION STIR PROCESSED AZ31 WITH SiCP

2008 ◽  
Vol 22 (18n19) ◽  
pp. 2879-2885 ◽  
Author(s):  
M. NAJAFI ◽  
A. M. NASIRI ◽  
A. H. KOKABI
Keyword(s):  
Grain Size ◽  
Magnesium Alloys ◽  
Base Material ◽  
Ultrafine Grain ◽  
Matrix Composites ◽  
Magnesium Matrix Composites ◽  
Friction Stir ◽  
Sic Particles ◽  
Ultrafine Grain Size ◽  
Potential Weight

Friction stir processing (FSP) is a novel technique to produce ultrafine grained materials. Most of the researches conducted on FSP focus on aluminum alloys. Despite the potential weight reduction that can be achieved by using magnesium alloys, a few researches have been reported on FSP of magnesium alloys. In this work, the possibility of using FSP with and without SiC particles to modify the microstructure and hardness of commercial AZ31 is examined. SiC particles were uniformly dispersed into an AZ31 matrix by FSP. The mean grain size of the stir zone with the SiC particles was obviously smaller than the same zone without the SiC particles. SiC reinforced magnesium matrix composites created by FSP with cooling rapidly the plate that exhibit ultrafine grain size approximately 1μm and nearly doubled the hardness of the base material.

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