scholarly journals Research on oxidation phenomenon during titanium machining and its prevention

2020 ◽  
Vol 20 (2) ◽  
pp. 77-85
Author(s):  
Ikuo TANABE ◽  
Yuya GOI ◽  
Yuko TANABE
Keyword(s):  
Titanium Machining

Mechanism of Variable Helix Tools in Suppressing Chatter Using Process Damping for Machining Titanium Alloys at Low Cutting Speed

2013 ◽  
Vol 773-774 ◽  
pp. 370-376
Author(s):  
Muhammad Adib Shaharun ◽  
Ahmad Razlan Yusoff ◽  
Mohammad S. Reza
Keyword(s):  
Titanium Alloy ◽  
Cutting Speed ◽  
Milling Process ◽  
Cutting Process ◽  
Chatter Vibration ◽  
Process Damping ◽  
High Cutting Speed ◽  
Titanium Machining ◽  
Different Types ◽  
Variable Helix

Titanium is difficult-to-cut materials due to its poor machinability and thermal conductivity when machining at high cutting speed. To overcome this machining titanium alloy problem, this study in interaction between machining structural system and the cutting process are very important. One of the main problems in the cutting process is chatter vibration. Due to chatter problem, the mechanism to suppress chatter named, process damping is a useful method can be manipulated to improve the limited productivity of titanium machining at low speed machining in milling process. In the present study, experiment are conducted to evaluate and study the process damping mechanism in milling using different types of variable tools geometries. These tools are variable he-lix/uniform pitch, variable pitch/uniform helix and variable helix and pitch and uniform helix/pitch. The result showed that the variable helix and pitch tools is very significantly improve process damping performance in machining titanium alloy compare to traditional of regular tools and other irregular tools.

Sintered Nickel Casing for Irradiation Targets

2016 ◽  
Vol 869 ◽  
pp. 484-489
Author(s):  
R.S.L. Miyano ◽  
H. Takiishi ◽  
E.P. Soares ◽  
A.M. Saliba-Silva ◽  
J.L. Rossi
Keyword(s):  
Stainless Steel ◽  
High Purity ◽  
Nickel Powder ◽  
Nuclear Reactor ◽  
Mercury Porosimetry ◽  
Boundary Surface ◽  
Hydraulic Press ◽  
Titanium Machining ◽  
Powder Samples ◽  
Metallic Cylinder

The aim of this work was to develop an alternative way to obtain casings used with irradiation targets containing uranium, for the production of the radionuclide Mo-99-Tc99m. The targets used for the production of Mo-99 are materials containing U-235 designed to be irradiated in a nuclear reactor. Usually these targets are encapsulated in aluminum or stainless steel. The idea here is to obtain casings by encapsulating a uranium button or a metallic cylinder with compacted and sintered nickel powder, this serving as a sealing for the fissile products occurring during U-235 irradiation. The sintered high purity nickel powder samples were compacted in uniaxial hydraulic press at 195 MPa. The sintering of the samples was carried out in an open-air furnace in an atmosphere with a certain control using titanium-machining chips at 600 °C. The samples bulk density was evaluated by the Archimedes' principle. The porosity of 20.08% was measured by mercury porosimetry. The microstructure was investigated by scanning microscopy revealing interconnected porosity and nickel oxide at the particles boundary surface. The results obtained by sintering of nickel powder according to the experimental undertaken, indicate the feasibility of achieving a casing for uranium targets.

scholarly journals High performance computing simulations to identify process parameter designs for profitable titanium machining

2017 ◽  
Vol 43 ◽  
pp. 235-247 ◽  
Author(s):  
Mathew Kuttolamadom ◽  
Joshua Jones ◽  
Laine Mears ◽  
James Von Oehsen ◽  
Thomas Kurfess ◽  
...  
Keyword(s):  
High Performance Computing ◽  
High Performance ◽  
Process Parameter ◽  
Titanium Machining ◽  
Performance Computing

scholarly journals The influence of cooling techniques on cutting forces and surface roughness during cryogenic machining of titanium alloys

2016 ◽  
Vol 36 (1) ◽  
pp. 12-17 ◽  
Author(s):  
Iwona Wstawska ◽  
Krzysztof Ślimak
Keyword(s):  
Surface Roughness ◽  
Titanium Alloys ◽  
Cutting Forces ◽  
Positive Influence ◽  
Cryogenic Machining ◽  
Specific Strength ◽  
Titanium Machining ◽  
Starting Point ◽  
The Cost ◽  
Parameter Values

Abstract Titanium alloys are one of the materials extensively used in the aerospace industry due to its excellent properties of high specific strength and corrosion resistance. On the other hand, they also present problems wherein titanium alloys are extremely difficult materials to machine. In addition, the cost associated with titanium machining is also high due to lower cutting velocities and shorter tool life. The main objective of this work is a comparison of different cooling techniques during cryogenic machining of titanium alloys. The analysis revealed that applied cooling technique has a significant influence on cutting force and surface roughness (Ra parameter) values. Furthermore, in all cases observed a positive influence of cryogenic machining on selected aspects after turning and milling of titanium alloys. This work can be also the starting point to the further research, related to the analysis of cutting forces and surface roughness during cryogenic machining of titanium alloys.

Effect of fluid concentration in titanium machining with an atomization-based cutting fluid (ACF) spray system

2013 ◽  
Vol 15 (4) ◽  
pp. 419-425 ◽  
Author(s):  
Chandra Nath ◽  
Shiv G. Kapoor ◽  
Anil K. Srivastava ◽  
Jon Iverson
Keyword(s):  
Cutting Fluid ◽  
Spray System ◽  
Titanium Machining ◽  
Fluid Concentration

scholarly journals Prediction of Cutting Forces at 2D Titanium Machining

2014 ◽  
Vol 69 ◽  
pp. 81-89 ◽  
Author(s):  
Diana-Andreea Coroni ◽  
Sorin-Mihai Croitoru
Keyword(s):  
Cutting Forces ◽  
Titanium Machining

Microstructure-Mechanics Interactions in Modeling Chip Segmentation during Titanium Machining

CIRP Annals ◽  
2002 ◽  
Vol 51 (1) ◽  
pp. 71-74 ◽  
Author(s):  
R. Shivpuri ◽  
J. Hua ◽  
P. Mittal ◽  
A.K. Srivastava ◽  
G.D. Lahoti
Keyword(s):  
Titanium Machining

On Cutting Temperature Measurement During Titanium Machining With an Atomization-Based Cutting Fluid Spray System

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Alexander C. Hoyne ◽  
Chandra Nath ◽  
Shiv G. Kapoor
Keyword(s):  
Cutting Temperature ◽  
Cutting Fluid ◽  
Dry Machining ◽  
Temperature Level ◽  
Spray System ◽  
Titanium Machining ◽  
Dry Conditions ◽  
System Temperature ◽  
Cutting Zone ◽  
Fluid Penetration

The poor thermal conductivity and low elongation-to-break ratio of titanium lead to the development of extreme temperatures (in excess of 550 °C) localized in the tool–chip interface during machining of its alloys. At such temperature level, titanium becomes highly reactive with most tool materials resulting in accelerated tool wear. The atomization-based cutting fluid (ACF) spray system has recently been demonstrated to improve tool life in titanium machining due to good cutting fluid penetration causing the temperature to be reduced in the cutting zone. In this study, the cutting temperatures are measured both by inserting thermocouples at various locations of the tool–chip interface and the tool–work thermocouple technique. Cutting temperatures for dry machining and machining with flood cooling are also characterized for comparison with the ACF spray system temperature data. Findings reveal that the ACF spray system more effectively reduces cutting temperatures over flood cooling and dry conditions. The tool–chip friction coefficient indicates that the fluid film created by the ACF spray system also actively penetrates the tool–chip interface to enhance lubrication during titanium machining.

The Effects of Structural and Servo Modes in Titanium Machining

Manufacturing ◽  
2002 ◽  
Author(s):  
K. Scott Smith ◽  
Bethany A. Lamy
Keyword(s):  
Natural Frequencies ◽  
Metal Removal ◽  
Removal Rate ◽  
Mode Shapes ◽  
Metal Removal Rate ◽  
Tool Selection ◽  
Titanium Machining ◽  
The Stability ◽  
Adjustment Of Parameters ◽  
Cutting Speeds

This paper shows that in titanium machining the metal removal rate may be limited by factors including the dynamic characteristics of the frame of the machine and the servo. Self-excited vibrations related to these components led to poor cutting performance and tool breakage. Measurements of the acceleration were made during a number of cuts. In combination with impact tests, these measurements were used to identify the natural frequencies and mode shapes associated with the structural modes. These measurements ultimately led to adjustment of parameters in the control loop (to modify the servo dynamics), to special tool selection (to disturb the regeneration), and to the choice of stable cutting speeds (to take advantage of the stability lobes). The resulting cutting conditions significantly improved the metal removal rate. The nature of current titanium machining makes the structural modes particularly problematic, and it is important to measure and consider them during process planning.

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