scholarly journals Experimental Study on Ultra-Precision Polishing of Ti-6Al-4V by Ultraviolet-Induced Nanoparticle Colloid Jet Machining

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5014
Author(s):  
Xiaozong Song ◽  
Xiaorong Wang ◽  
Shun Wang ◽  
Shengkai Liu ◽  
Shundong Ge
Keyword(s):  
Chemical Interaction ◽  
Removal Rate ◽  
Workpiece Surface ◽  
Β Phase ◽  
Longitudinal Residual Stress ◽  
Before And After ◽  
Ultra Precision ◽  
Scale Surface ◽  
Nanoparticle Colloid ◽  
Differential Spectroscopy

Ti-6Al-4V is widely used in various fields of modern industry, but it is difficult to obtain an ultra-smooth surface of Ti-6Al-4V due to its poor machinability. In this article, ultraviolet-induced (UV-induced) nanoparticle colloid jet machining was utilized to carry out ultra-precision polishing of Ti-6Al-4V to improve the surface quality. The results of infrared differential spectroscopy before and after polishing show that new chemical bonds such as Ti-O-Ti (Al-O-Ti and V-O-Ti) appear on the Ti-6Al-4V workpiece surface, which indicates that the material of Ti-6Al-4V workpiece is removed through the chemical interaction between TiO2 nanoparticles and workpiece surface in the process of UV-induced nanoparticle colloid jet machining. The comparison of metallographic structure of Ti-6Al-4V before and after polishing shows that the chemical activity and material removal rate of the primary α phase in Ti-6Al-4V is higher than that of the remnant β phase in UV-induced nanoparticle colloid jet machining, which lead to the well-distributed nano-scale surface peaks and valleys at regular intervals on the polished Ti-6Al-4V workpiece surface. After polishing, the longitudinal residual stress on the surface of Ti-6Al-4V workpiece decreases from 75 MPa to 67 MPa and the transverse stress decreases from 13 MPa to 3 MPa. The surface roughness of Ti-6Al-4V workpiece is reduced from Sa 76.7 nm to Sa 2.87 nm by UV-induced nanoparticle colloid jet machining.

Ultra-Precision Shaping and Ultra-Smooth Polishing Investigation of High-Purity Quartz Glass in Nanoparticle Colloid Jet Machining

2012 ◽  
Vol 426 ◽  
pp. 396-399 ◽  
Author(s):  
Xiao Zong Song ◽  
Yong Zhang ◽  
Fei Hu Zhang
Keyword(s):  
Quartz Glass ◽  
High Purity ◽  
Glass Surface ◽  
Morphological Characteristics ◽  
Surface Profile ◽  
Processing Technique ◽  
Surface Shape ◽  
Before And After ◽  
Ultra Precision ◽  
Nanoparticle Colloid

In this paper, ultra-precision shaping and ultra-smooth polishing investigations have been done upon a high-purity quartz glass substrate with an aspheric surface in nanoparticle colloid jet machining, which is an ultra smooth surface processing technique utilizing surface chemical reaction between work surface atoms and nanoparticles to remove the uppermost surface atoms. The shaping and polishing characters of high-purity quartz glass in nanoparticle colloid jet machining has been researched. The surface profile of the high-purity quartz glass workpiece before and after shaping has been measured by surface profilometer. And the surface microscopic morphological characteristics of high-purity quartz glass surface polished by nanoparticle colloid jet machining have been observed by atomic force microscopy (AFM). The measurement results indicate that nanoparticle colloid jet machining has good shaping ability for surface shape correction in ultra-precision machining. And the AFM observation results show that the roughness of the high-purity quartz glass surface has been reduced from 1.919 nm RMS to 0.784 nm RMS by nanoparticle colloid jet machining.

Ultra-Precision Shaping and Polishing Experiments in Nanoparticle Colloid Jet Machining

2011 ◽  
Vol 291-294 ◽  
pp. 1759-1763 ◽  
Author(s):  
Xiao Zong Song ◽  
Yong Zhang ◽  
Fei Hu Zhang
Keyword(s):  
Atomic Force Microscopy ◽  
Morphological Characteristics ◽  
Surface Profile ◽  
Surface Shape ◽  
Workpiece Surface ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ultra Precision ◽  
Nanoparticle Colloid ◽  
Observation Results

In this paper, ultra-precision shaping and polishing experiments have been done to research the shaping and polishing characters of nanoparticle colloid jet machining. A high-purity quartz glass sample with aspheric surface profile was employed as workpiece and polished by nanoparticle colloid jet machining. We utilized surface profilometer to measure the surface profiles of workpiece before and after shaping by nanoparticle colloid jet machining. The measurement results indicate that the nanoparticle colloid jet machining has good shaping ability to satisfy the demands for surface shape correction in ultra-precision machining. Atomic force microscopy (AFM) was utilized to observe the surface microscopic morphological characteristics of the workpiece surface polished by nanoparticle colloid jet machining. The observation results show that the roughness of the workpiece surface has been reduced from 1.919 nm RMS to 0.784 nm RMS by nanoparticle colloid jet machining. Based on the atomic force microscopy observation results, power spectral density analyses have been done to evaluate the polishing performance of the nanoparticle colloid jet machining.

Study on Single-Plane Biaxial Balance Monitor System in ULTRA-Precision Grinding

2006 ◽  
Vol 304-305 ◽  
pp. 251-255
Author(s):  
L. Zheng ◽  
Yin Biao Guo ◽  
Z.Z. Wang
Keyword(s):  
Mutual Influence ◽  
Machining Accuracy ◽  
Monitor System ◽  
Machining Parameters ◽  
Precision Grinding ◽  
Single Plane ◽  
Workpiece Surface ◽  
Surface Error ◽  
Vibration Data ◽  
Ultra Precision

This paper puts forward an intelligent single-plane biaxial balance monitor system, which is used in ultra-precision grinding. It adopts the method of single-plane balance correction for the vibration of wheel and workpiece. And this system can also be used for integral balance. For ultra-precision grinding, caused by the mutual influence of the vibration of wheel and workpiece, there will be a ripple on the workpiece surface, which is mainly influenced by the frequency ratio of wheel to workpiece, the feed rate and the vibration of wheel and workpiece. This system can improve the machining accuracy, reduce the surface error of workpiece and appraise the integrated machining result, by analyzing the vibration data of wheel and workpiece and adjusting machining parameters.

Tool Surface Topographies for Controlling Friction and Wear in Metal-Forming Processes

1998 ◽  
Vol 120 (3) ◽  
pp. 517-527 ◽  
Author(s):  
Simon Sheu ◽  
Louis G. Hector ◽  
Owen Richmond
Keyword(s):  
Surface Topography ◽  
Metal Forming ◽  
Friction And Wear ◽  
Workpiece Surface ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Single Scale ◽  
Surface Topographies ◽  
Tool Surface ◽  
Scale Surface

A conceptual framework is introduced for the design of tool surface topographies in bulk metal forming processes. The objective of the design is to control friction to desired levels while minimizing wear of the workpiece and tool surfaces and adhesive metal transfer between the workpiece and tool. Central to the design framework are the tool/workpiece interface properties of lubricant retention and interface permeability. Lubricant retention refers to the capacity of an interface to retain lubricant rather than freely channel it to the exterior of the tool/workpiece conjunction. Permeability refers to the capacity to distribute lubricant to all areas within the conjunction. These properties lead to the concept of two-scale surface topography consisting of a fine scale background of interconnected channels on which is superimposed an array of coarser-scale cavities. Control of friction and wear is achieved by designing the tool surface topographies at these two scales to address the unique tribological conditions of specific bulk metal forming processes. The coarser scale is designed to ensure adequate supply of lubricant within the conjunction. The finer scale is designed to ensure adequate delivery of lubricant to all parts of the conjunction where nascent workpiece surface is being formed. The design concepts are illustrated with results from laboratory experiments using the rolling process as an example, and comparing the performance of various roll surface topographies under similar processing conditions. A two-scale surface topography consisting of hemispherical cavities distributed across a background surface of finer scale, interconnected channels was shown to reduce friction compared to a single-scale ground finish, but not as much as a single-scale coarse topography consisting of densely-packed cavities produced by an electrical discharge treatment. On the other hand, the smoother cross-sections of the cavities, especially when elongated in the direction of greatest relative motion, produced significantly less wear than either of the single-scale tool surface treatments. It is concluded that two-scale engineering of tool surface topographies based upon the concepts of lubricant retention and interface permeability can provide a broad basis for achieving desired levels of interface friction while minimizing workpiece surface wear and adhesive material transfer in many metal-forming processes.

Mitochondrial Ca2+ uptake is important over low [Ca2+]i range in arterial smooth muscle

2002 ◽  
Vol 283 (6) ◽  
pp. H2431-H2439 ◽  
Author(s):  
Tomoko Kamishima ◽  
John M. Quayle
Keyword(s):  
Smooth Muscle ◽  
Decay Time ◽  
Removal Rate ◽  
Arterial Smooth Muscle ◽  
Carbonyl Cyanide ◽  
Before And After ◽  
Intracellular Ca ◽  
Arterial Smooth Muscle Cells ◽  
Time Required ◽  
Loaded Voltage

Mitochondrial Ca2+ uptake is usually thought to occur only when intracellular Ca2+concentration ([Ca2+]i) is high. We investigated whether mitochondrial Ca2+ removal participates in shaping [Ca2+]i signals in arterial smooth muscle over a low [Ca2+]irange. [Ca2+]i was measured using fura 2-loaded, voltage-clamped cells from rat femoral arteries. Both diazoxide and carbonyl cyanide m-chlorophenylhydrazone (CCCP) depolarized the mitochondria. Diazoxide application increased resting [Ca2+]i, suggesting that Ca2+ is sequestered in mitochondria. Over a low [Ca2+]i range, diazoxide and CCCP slowed Ca2+ removal rate, determined after a brief depolarization. When [Ca2+]i was measured during sustained depolarization to −30 mV, CCCP application increased [Ca2+]i. When Ca2+ transients were repeatedly evoked by caffeine applications, CCCP application elevated resting [Ca2+]i. Caffeine-induced Ca2+ transients were compared before and after CCCP application using the half decay time, or time required to reduce increase in [Ca2+]i by 50% ( t ½). CCCP treatment significantly increased t ½. These results suggest that Ca2+ removal to mitochondria in arterial smooth muscle cells may be important at a low [Ca2+]i.

scholarly journals Effect of Mo, V and Zr on the microstructure and mechanical properties of Ti2AlNb alloys

2020 ◽  
Vol 321 ◽  
pp. 08003
Author(s):  
Yujun Du ◽  
Xianghong Liu ◽  
Jinshan Li ◽  
Wenzhong Luo ◽  
Yongsheng He ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Melting Process ◽  
Phase Region ◽  
Arc Furnace ◽  
Micro Hardness ◽  
Β Phase ◽  
Before And After ◽  
B2 Phase ◽  
O Phase

Small button ingots of Ti2AlNb alloys with different contents of Mo, V and Zr were melted by vacuum non-consumable arc furnace. Due to the rapid cooling rate during melting process, only β grains without precipitation were observed in most of the button ingots and no regular phenomenon was found. However, when the samples were heated to β phase region and then furnace cooled to room temperate, different morphologies and quantities of primary α phase and second O phase formed from the β grains of different samples. It is suggested that the morphology of α phase was changed from lamellar to quadrilateral with increasing V and the lath O increased with increasing Zr. Besides, the residual β/B2 phase increased with increasing Mo and V. The EDS results showed that Al and Zr were enriched in α phase whereas Nb, Mo and V were enriched in β/B2 phase. The micro-hardness of these samples before and after heat treatment was detected and the micro-hardness increased with increasing Zr and decreasing Mo and V.

Research on Ultra-Precision Machining Technology for KTP

2004 ◽  
Vol 471-472 ◽  
pp. 473-476 ◽  
Author(s):  
Ju Long Yuan ◽  
Fei Yan Lou ◽  
Zhi Wei Wang ◽  
M. Chang ◽  
W.P. Du ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Frequency Conversion ◽  
Removal Rate ◽  
Nonlinear Coefficient ◽  
Damage Threshold ◽  
Green Laser ◽  
Machining Process ◽  
Polished Surface ◽  
Nonlinear Frequency ◽  
Ultra Precision

Potassium Titanium Oxide Phosphate (KTP) is a new nonlinear frequency-conversion crystal. It has chemical stability, high nonlinear coefficient, high damage threshold, easily-polished surface, and a broad transparency range. It is be used in solid green laser with medium and low power widely. The requirement for surface roughness is less than 1nm.In this paper, the removal rate and surface roughness are discussed with different velocity, pressure and size of abrasive powder. In order to satisfy the requirement, new polishing techniques with ultra-precision plane polishing machine (Nanopoli-100), and fine AL2O3, SiO2 powders are proposed in this study. The final surface roughness of the KTP is less than 1nm.The machining process and characteristics are also indicated.

INVESTIGATION OF SINGLE-POINT DRESSING OVERLAP RATIO AND DIAMOND-ROLL DRESSING INTERFERENCE ANGLE ON SURFACE ROUGHNESS IN GRINDING

2010 ◽  
Vol 34 (2) ◽  
pp. 295-308 ◽  
Author(s):  
Akram Saad ◽  
Robert Bauer ◽  
Andrew Warkentin
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Empirical Model ◽  
Material Removal ◽  
Removal Rate ◽  
Single Point ◽  
Experimental Conditions ◽  
Workpiece Surface ◽  
Different Depths ◽  
Overlap Ratio

This paper investigates the effect of both single-point and diamond-roll dressing techniques on the workpiece surface roughness in grinding. Two empirical surface roughness models are studied – one that incorporates single-point dressing parameters, and another that incorporates diamond-roll dressing parameters. For the experimental conditions used in this research, the corresponding empirical model coefficients are found to have a linear relationship with the inverse of the overlap ratio for single-point dressing and the interference angle for diamond-roll dressing. The resulting workpiece surface roughness models are then experimentally validated for different depths of cut, workpiece speeds and dressing conditions. In addition, the models are used to derive a relationship between overlap ratio for single-point dressing, and interference angle for diamond-roll dressing such that both dressing techniques produce a similar surface finish for a given material removal rate.

A Comparison of Generator Mode on the Performance of Finish EDM of AISI P20 Tool Steel

2004 ◽  
Author(s):  
Fred L. Amorim
Keyword(s):  
Tool Steel ◽  
Process Parameters ◽  
Material Removal ◽  
Removal Rate ◽  
Technical Information ◽  
Relaxation Mode ◽  
Workpiece Surface ◽  
Aisi P20 ◽  
Edm Process ◽  
Aisi P20 Steel

The AISI P20 steel is applied by the tooling industry as material for injection molding tools. It is known that the EDM process parameters technology installed at the majority of CNC EDM machines do not cover some of the necessities of the tooling industry. So, the customers are required to develop their own process parameters. In order to provide useful technical information to the industry an experimental investigation on the EDM of the AISI P20 tool steel under finish machining has been carried out. The material removal rate Vw, volumetric relative wear v and workpiece surface texture Ra, which are representative of EDM performance aspects, were analyzed against the variation of some of the most important EDM electrical variables using copper tool electrodes under positive and negative polarity. The EDM machine generator was also programmed to actuate under isoenergetic mode and relaxation mode. The results are discussed and some appropriate parameters for EDM of AISI P20 are suggested.

Effects of the Profile of Workpiece Surface on Material Removal Rate Distribution in Polishing Process

2016 ◽  
Vol 851 ◽  
pp. 149-154
Author(s):  
Zhen Gang Wu ◽  
Dong Shan He ◽  
Ping Zhou ◽  
Dong Ming Guo
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Surface Profile ◽  
Prediction Method ◽  
Quantitative Prediction ◽  
Polishing Process ◽  
Workpiece Surface ◽  
Coefficient Distribution ◽  
Polishing Pad

Accurate prediction of the material removal rate (MRR) distribution is very important for the control of the polishing process. However, the widely used prediction method of MRR based on the Preston equation is still incapable of predicting the roll-off phenomenon in polishing process. One of the reasons is that many of the researchers’ neglected the effect of the surface profile of the workpiece on the MRR. In this paper, the evolutionary process of MRR distribution with the change of surface profile using two different polishing pad is studied, it is found that MRR varies gradually with the change of surface profile and tends to be uniform finally. Based on the analysis of contact pressure considering the actual surface profile of workpiece and modified Preston equation, the distribution of MRR is analyzed. It is found that the Preston coefficient distribution on workpiece surface is stable when the surface profile variation is small and shows obvious differences from the center to the edge of the workpiece. Through the comparison it is found that correlation between the regularities of Preston coefficient distribution and the type of polishing pad is significant. The research results in this paper will play an important guiding role in the quantitative prediction method research of polishing process.

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