Chip Topography for Ductile-Regime Machining of Germanium

1994 ◽  
Vol 116 (2) ◽  
pp. 263-266 ◽  
Author(s):  
W. S. Blackley ◽  
R. O. Scattergood
Keyword(s):  
Diamond Turning ◽  
Cutting Depth ◽  
Machined Surface ◽  
Free Surfaces ◽  
Brittle Transition ◽  
Critical Cutting Depth ◽  
Independent Estimate ◽  
Ductile Regime Machining ◽  
Ductile To Brittle Transition ◽  
Insight Into

Ductile-regime response during the diamond turning of brittle germanium crystals is evident from the damage-free surfaces obtained. The nature of the ductile-regime processes cannot be determined by examination of the final machined surface itself. Machining chips were characterized using scanning electron microscopy. The chip topography provides insight into the ductile-to-brittle transition that occurs along the tool nose. A detailed examinaiton of the chips provides an independent estimate of the critical cutting depth for the transition.

Single Point Diamond Turning of CVD Coated Silicon Carbide

2006 ◽  
Author(s):  
Biswarup Bhattacharya ◽  
John A. Patten ◽  
Jerry Jacob
Keyword(s):  
Silicon Carbide ◽  
Single Point ◽  
Diamond Turning ◽  
Depth Of Cut ◽  
Critical Depth ◽  
Machined Surface ◽  
Brittle Transition ◽  
Ductile Regime Machining ◽  
Critical Depth Of Cut ◽  
Ductile To Brittle Transition

Scratching experiments, using diamond styli and single point diamond tools, were performed to simulate Single Point Diamond Turning (SPDT). The results of these experiments were used to determine if a ductile response is possible, and then to determine the critical depth of cut or penetration depth for the ductile to brittle transition (DBT). The depths of the scratches produced at different loads were measured and correlated to the ductile and brittle response of the material. The DBT depth for Chemically Vapor Deposited (CVD) coated Silicon Carbide (SiC) samples was determined. The analysis for the critical depth (DBT) did confirm the possibility for SPDT of CVD coated SiC in the ductile regime. These results were further used for SPDT of CVD SiC. Post experimental analysis of the machined surface did reveal a final surface roughness of 8–20nm, successfully demonstrating ductile regime machining of CVD coated SiC.

scholarly journals The nucleation of the Izmit and Düzce earthquakes: Some mechanical logic on where and how ruptures began

2021 ◽  
Author(s):  
Michel Bouchon ◽  
Hayrullah Karabulut ◽  
Mustafa Aktar ◽  
Serdar Özalaybey ◽  
Jean Schmittbuhl ◽  
...  
Keyword(s):  
Strike Slip ◽  
Seismic Events ◽  
Fault Geometry ◽  
Brittle Transition ◽  
The North ◽  
Impending Rupture ◽  
Natural Tendency ◽  
Ductile To Brittle Transition ◽  
Mechanical Logic ◽  
Rupture Speed

Summary In spite of growing evidence that many earthquakes are preceded by increased seismic activity, the nature of this activity is still poorly understood. Is it the result of a mostly random process related to the natural tendency of seismic events to cluster in time and space, in which case there is little hope to ever predict earthquakes? Or is it the sign that a physical process that will lead to the impending rupture has begun, in which case we should attempt to identify this process. With this aim we take a further look at the nucleation of two of the best recorded and documented strike-slip earthquakes to date, the 1999 Izmit and Düzce earthquakes which ruptured the North Anatolian Fault over ∼200 km. We show the existence of a remarkable mechanical logic linking together nucleation characteristics, stress loading, fault geometry and rupture speed. In both earthquakes the observations point to slow aseismic slip occurring near the ductile-to-brittle transition zone as the motor of their nucleation.

scholarly journals Probing the Statistical Validity of the Ductile-to-Brittle Transition in Metallic Nanowires Using GPU Computing

2013 ◽  
Vol 9 (12) ◽  
pp. 5558-5566 ◽  
Author(s):  
William R. French ◽  
Amulya K. Pervaje ◽  
Andrew P. Santos ◽  
Christopher R. Iacovella ◽  
Peter T. Cummings
Keyword(s):  
Gpu Computing ◽  
Metallic Nanowires ◽  
Brittle Transition ◽  
Statistical Validity ◽  
Ductile To Brittle Transition

scholarly journals Fracture and Ductile-to-Brittle Transition Characteristics of Molybdenum by Impact and Static Bend Tests

1995 ◽  
Vol 36 (4) ◽  
pp. 504-510 ◽  
Author(s):  
Yutaka Hiraoka ◽  
Hiroaki Kurishita ◽  
Minoru Narui ◽  
Hideo Kayano
Keyword(s):  
Brittle Transition ◽  
Bend Tests ◽  
Ductile To Brittle Transition

Effects of thermal treatments on the ductile to brittle transition of MANET steel

1996 ◽  
Vol 233-237 ◽  
pp. 248-252 ◽  
Author(s):  
P. Gondi ◽  
R. Montanari ◽  
A. Sili ◽  
M.E. Tata
Keyword(s):  
Thermal Treatments ◽  
Brittle Transition ◽  
Ductile To Brittle Transition
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