Research on the critical condition of Brittle-Ductile Transition about Micro-Milling of KDP crystal and experimental verification

2015 ◽  
Vol 16 (2) ◽  
pp. 351-359 ◽  
Author(s):  
Yong Xiao ◽  
Ming-Jun Chen ◽  
Yan-Ting Yang ◽  
Jian Cheng
Keyword(s):  
Experimental Verification ◽  
Critical Condition ◽  
Micro Milling ◽  
Kdp Crystal ◽  
Brittle Ductile Transition

Research on Influence of Crystal KDP Anisotropy on Critical Condition of Brittle-Ductile Transition in Ultra-Precision Cutting

2006 ◽  
Vol 315-316 ◽  
pp. 725-730 ◽  
Author(s):  
Ming Jun Chen ◽  
Ying Chun Liang ◽  
Jing He Wang ◽  
Shen Dong
Keyword(s):  
Surface Quality ◽  
Critical Condition ◽  
Influence Factors ◽  
Potassium Dihydrogen Phosphate ◽  
Experimental Results ◽  
Depth Of Cut ◽  
Dihydrogen Phosphate ◽  
Brittle Ductile Transition ◽  
Ultra Precision

In order to machine high accuracy Potassium Dihydrogen Phosphate (KDP) crystal part, the indentation experiments are carried out with various loads and various orientation angles. The experimental results show that the critical condition of brittle-ductile transition of KDP has strong anisotropy. Therefore, the influence factors on the surface quality of crystal KDP was discussed, it is shown that influences of the tool's geometry parameter, feed rate and Nominal depth of cut etc on the surface quality of KDP are main. Afterwards the cutting experimental study on crystal KDP material is carried out. The experimental results show that the super-smooth surface quality only can be obtained while KDP is ultra-precision machined in ductile mode.

Critical Cutting Condition for Brittle-Ductile Transition of KDP Crystals in Ultra-Precision Machining

2007 ◽  
Vol 329 ◽  
pp. 409-414 ◽  
Author(s):  
Jing He Wang ◽  
Ming Jun Chen ◽  
Shen Dong ◽  
H.X. Wang ◽  
J.H. Zhang ◽  
...  
Keyword(s):  
Mechanical Characteristics ◽  
Crystal Plane ◽  
Precision Machining ◽  
Cutting Condition ◽  
Kdp Crystal ◽  
Crystal Anisotropy ◽  
Brittle Ductile Transition ◽  
Ultra Precision ◽  
Kdp Crystals ◽  
Variation Rule

In this paper, mechanical characteristics of KDP crystal anisotropy are analysed theoretically. Vickers indentation experiments are adopted to validate the variation rule of hardness and fracture toughness in different orientation of KDP crystal plane (100), and a model to calculate critical cutting thickness of brittle-ductile transition is proposed for the KDP crystals. The result shows that, on the crystal plane (100), the minimum value of critical cutting thickness of KDP crystal in brittle-ductile transition appears in the direction [110], but the maximum appears in the direction [010]. Finally, the ultra-precision machining of KDP crystal is performed, and the results agree well with the theoretical conclusions. Super-smooth surface with a roughness RMS of 6.6nm is reached as machined in the crystal direction [010], and 11.2nm to the direction [110].

Effects of Ion Beam Milling on Surface Topography

1973 ◽  
Vol 31 ◽  
pp. 84-85
Author(s):  
P.G. Pawar ◽  
P. Duhamel ◽  
G.W. Monk
Keyword(s):  
Surface Topography ◽  
Ion Beam ◽  
Solid Material ◽  
Beam Current ◽  
Atomic Mass ◽  
Micro Milling ◽  
Ion Milling ◽  
Controlled Atmospheres ◽  
Milling Operations ◽  
Sufficient Energy

A beam of ions of mass greater than a few atomic mass units and with sufficient energy can remove atoms from the surface of a solid material at a useful rate. A system used to achieve this purpose under controlled atmospheres is called an ion miliing machine. An ion milling apparatus presently available as IMMI-III with a IMMIAC was used in this investigation. Unless otherwise stated, all the micro milling operations were done with Ar+ at 6kv using a beam current of 100 μA for each of the two guns, with a specimen tilt of 15° from the horizontal plane.It is fairly well established that ion bombardment of the surface of homogeneous materials can produce surface topography which resembles geological erosional features.

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