A Metallographic Preparation Method for Three-Dimensional Microstructural Characterization of Machining Chips

2021 ◽  
Vol 58 (10) ◽  
pp. 644-661
Author(s):  
S. Fang ◽  
A. Frank
Keyword(s):  
Preparation Method ◽  
Microstructural Characterization ◽  
Geometric Features ◽  
Abrasive Machining ◽  
Machining Processes ◽  
Important Indicator ◽  
Statistical Characterization ◽  
Vast Number ◽  
Metallographic Preparation

Abstract Chip formation is an important indicator of machining processes. Statistical characterization of machining chips’ geometric features can offer crucial information for evaluating the stability and productivity of the machining processes. In abrasive machining processes, an abundance of small chips are produced by the vast number of abrasives exposed to the cutting surfaces. Geometric features of abrasives, such as shape, dimension, and distribution, may be hierarchically passed on to the chips. Similar to those of the abrasives, geometric features of the chips may also vary to a certain extent and conform to some statistical distribution. To verify these characteristics, a metallographic preparation method in connection with chips formed in abrasive machining processes is proposed in this study. Challenges in collecting and segmenting chips have been successfully overcome through several steps using ultrasonic bath cleaning and powder cold embedding methods. Finally, a considerable amount of chips was formed and uniformly embedded in a resin mold, ready for microscopic characterization.

Microstructural Characterization of Automated Specimen Preparation for TEM Analysis

2000 ◽  
Vol 6 (S2) ◽  
pp. 528-529
Author(s):  
C. Urbanik Shannon ◽  
L. A. Giannuzzi ◽  
E. M. Raz
Keyword(s):  
Focused Ion Beam ◽  
Preparation Method ◽  
Ion Beam ◽  
Microstructural Characterization ◽  
Specimen Preparation ◽  
Tem Analysis ◽  
Area Of Interest ◽  
Transmission Electron ◽  
Preparation Techniques

Automated specimen preparation for transmission electron microscopy has the obvious advantage of saving personnel time. While some people may perform labor intensive specimen preparation techniques quickly, automated specimen preparation performed in a timely and reproducible fashion can significantly improve the throughput of specimens in an industrial laboratory. The advent of focused ion beam workstations for the preparation of electron transparent membranes has revolutionized TEM specimen preparation. The FIB lift-out technique is a powerful specimen preparation method. However, there are instances where the “traditional” FIB method of specimen preparation may be more suitable. The traditional FIB method requires that specimens must be prepared so that the area of interest is as thin as possible (preferably less than 50 μm) prior to FIB milling. Automating the initial specimen preparation for brittle materials (e.g., Si wafers) may be performed using the combination of cleaving and sawing techniques as described below.

Comparison of Free Abrasive Machining Processes in Wafer Manufacturing

2008 ◽  
Author(s):  
Chunhui Chung ◽  
Imin Kao
Keyword(s):  
Semiconductor Industry ◽  
Process Models ◽  
Machining Process ◽  
Abrasive Machining ◽  
Machining Processes ◽  
Wire Saw ◽  
Microelectronics Fabrication ◽  
Wafer Manufacturing ◽  
Free Abrasive

Free abrasive machining (FAM) processes, such as slicing using slurry wiresaws, lapping, and polishing, are very important manufacturing processes in wafer production for microelectronics fabrication. Since the materials in semiconductor industry are usually brittle, such as silicon, gallium arsenide, ... etc., the FAM processed can provide more gentle machining than the bonded abrasive machining process. Various machining theories and models have been developed to understand those processes. In this paper, the free abrasive machining processes in wafer manufacturing will be discussed in conjunction with the brittle material cracking theory. The modern slurry wire-saw slicing process and lapping process in wafer production will be presented with comparison to abrasive grits, manufacturing process models, characterization of manufacturing mechanisms, and properties of processes.

Microstructural characterization of CoPtCr/Cr thin film disks by cross-section TEM and elongated probe micro-diffraction

1991 ◽  
Vol 49 ◽  
pp. 762-763
Author(s):  
M.A. Parker ◽  
K.E. Johnson ◽  
C. Hwang ◽  
A. Bermea
Keyword(s):  
Magnetic Recording ◽  
Electron Probe ◽  
Microstructural Characterization ◽  
Crystallographic Structure ◽  
Recording Media ◽  
Layer By Layer ◽  
Cross Sectional ◽  
New Techniques ◽  
Polished Side

We have reported the dependence of the magnetic and recording properties of CoPtCr recording media on the thickness of the Cr underlayer. It was inferred from XRD data that grain-to-grain epitaxy of the Cr with the CoPtCr was responsible for the interaction observed between these layers. However, no cross-sectional TEM (XTEM) work was performed to confirm this inference. In this paper, we report the application of new techniques for preparing XTEM specimens from actual magnetic recording disks, and for layer-by-layer micro-diffraction with an electron probe elongated parallel to the surface of the deposited structure which elucidate the effect of the crystallographic structure of the Cr on that of the CoPtCr.XTEM specimens were prepared from magnetic recording disks by modifying a technique used to prepare semiconductor specimens. After 3mm disks were prepared per the standard XTEM procedure, these disks were then lapped using a tripod polishing device. A grid with a single 1mmx2mm hole was then glued with M-bond 610 to the polished side of the disk.

Microstructural Characterization of Au-Ge-Ni based ohmic contacts to GaAs/AlGaAs modfet device

1987 ◽  
Vol 45 ◽  
pp. 326-327
Author(s):  
A.K. Rai ◽  
A.K. Petford-Long ◽  
A. Ezis ◽  
D.W. Langer
Keyword(s):  
Contact Resistance ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Microstructural Characterization ◽  
Almost Everywhere ◽  
Spacer Layer ◽  
Good Contact ◽  
The Relationship ◽  
Lower Contact

Considerable amount of work has been done in studying the relationship between the contact resistance and the microstructure of the Au-Ge-Ni based ohmic contacts to n-GaAs. It has been found that the lower contact resistivity is due to the presence of Ge rich and Au free regions (good contact area) in contact with GaAs. Thus in order to obtain an ohmic contact with lower contact resistance one should obtain a uniformly alloyed region of good contact areas almost everywhere. This can possibly be accomplished by utilizing various alloying schemes. In this work microstructural characterization, employing TEM techniques, of the sequentially deposited Au-Ge-Ni based ohmic contact to the MODFET device is presented.The substrate used in the present work consists of 1 μm thick buffer layer of GaAs grown on a semi-insulating GaAs substrate followed by a 25 Å spacer layer of undoped AlGaAs.

Microstructural characterization of a cast RENi5-based alloy

1993 ◽  
Vol 51 ◽  
pp. 1176-1177
Author(s):  
G. M. Micha ◽  
L. Zhang
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Microstructural Characterization ◽  
Binary Compound ◽  
Nickel Metal ◽  
Cast Material ◽  
Nickel Metal Hydride ◽  
Transmission Electron ◽  
Cast Condition

RENi5 (RE: rare earth) based alloys have been extensively evaluated for use as an electrode material for nickel-metal hydride batteries. A variety of alloys have been developed from the prototype intermetallic compound LaNi5. The use of mischmetal as a source of rare earth combined with transition metal and Al substitutions for Ni has caused the evolution of the alloy from a binary compound to one containing eight or more elements. This study evaluated the microstructural features of a complex commercial RENi5 based alloy using scanning and transmission electron microscopy.The alloy was evaluated in the as-cast condition. Its chemistry in at. pct. determined by bulk techniques was 12.1 La, 3.2 Ce, 1.5 Pr, 4.9 Nd, 50.2 Ni, 10.4 Co, 5.3 Mn and 2.0 Al. The as-cast material was of low strength, very brittle and contained a multitude of internal cracks. TEM foils could only be prepared by first embedding pieces of the alloy in epoxy.

Microstructural Characterization of Open-Pore Metal Foams of Pure Metals

2015 ◽  
Vol 52 (2) ◽  
pp. 83-107 ◽  
Author(s):  
B. S. Mocker ◽  
A. M. Matz ◽  
N. Jost ◽  
P. Krug
Keyword(s):  
Microstructural Characterization ◽  
Metal Foams ◽  
Pure Metals

Microstructural characterization of a carbonitrided heat resisting alloy using focused ion beam-based techniques

2005 ◽  
Vol 22 (3) ◽  
pp. 351-358 ◽  
Author(s):  
S. Ford ◽  
D.J. Young ◽  
D. McGrouther ◽  
P.R. Munroe
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Microstructural Characterization
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