Correlation of the Volumetric Tool Wear Rate of Carbide Milling Inserts With the Material Removal Rate of Ti–6Al–4V

Abstract

The objective of this paper is to assess the correlation of volumetric tool wear (VTW) and wear rate o f carbide tools on the material removal rate (MRR) of titanium alloys. A pre viously developed methodology for assessing the worn tool material volume is utilized for quantifying the VTW of carbide tools when machining Ti-6Al-4V. To capture the tool response, controlled milling experiments are conducted at suitable corner points of the recommended feed-speed design space, for constant stock material removal volumes. For each case, the tool material volume worn away, as well as the corresponding volumetric wear profile evolution in terms of a set of geometric coefficients, is quantified-these are then related to the MRR. Further, the volumetric wear rate and the M-ratio (volume of stock removed to VTW) which is a measure of the cutting tool efficiency, are related to the MRR-these provide a tool-life based optimal MRR for profitability. This work not only elevates tool wear from a ID to 3D concept, but helps in assessing machining economics from a stock material-removal-ejficiency perspective as well.inadequacies were all the more pronounced in the case of tools catered to machining titanium alloys due to their typical complex geometric profiles involving high positive rake and relief angles. Consequently, a VTW quantification methodology was developed, standardized, and experimentally validated [1], This has potential to offer insights into the mechanics of wear itself from a 3D stand point, which is critical to a holistic understanding of the wear pro cess. Currently, tool wear is best tracked by a set of successive photomicrographs of the flank/rake face, at periodic instances dur ing the cut, which provide no information on how one wear profile led to another. An understanding of such progression/interactions will provide insights into the behavior and response of tool condi tion monitoring (TCM) parameters used for indirectly measuring tool wear, such as forces, vibrations, frequencies, etc., which was noted as a need in the recent ASME state-of-the-art paper on TCM [2], 2 Background 2.1 Qualitative Assessment of Tool Wear Quantifiers. CutCutting tool failure is most commonly quantified as a limiting measure of flank or crater wear or limits of surface finish, cutting force, vibration amplitude, etc. The standard measure of limiting tool life for carbide inserts is usually a uniform average flank depth (VBb) of about 0.3 mm or a localized wear depth (VBBmax) of about 0.6 mm [3], which can vary based on the application. Likewise, wear on the rake face is most commonly characterized by limiting values of crater wear depth (KT) as given by [4] KT = 0.06 + 0.3/where, / is the feed/rev. Note that this criterion was initially coined for single point turning tools with simple geometries. The ISO standards for tool life testing in milling [3] define 16 distinct tool deterioration phenomena for face milling, and 13 APRIL 2015, Vol. 137 / 021021-1

A probabilistic-based study on fused direct and indirect methods for tracking tool flank wear of Rene-108, nickel-based alloy

“…Considering a linear progress for the tool wear and assuming it as the first state of the system, the tool wear rate was assumed as the second state. Hence, a discretized state model can be written as equation (8), where MR denotes the volume of removed material. The state errors were added to equation 7as two independent normally distributed zero-mean noises with variances q 1 and q 2 , respectively…”

“…The 3D image of the worn insert was later used to find the correlation between volumetric tool wear rate and material removal rate in milling operation. 8…”

“…The 3D image of the worn insert was later used to find the correlation between volumetric tool wear rate and material removal rate in milling operation. 8 An alternative for direct methods of studying tool wear is indirect methods, in which directly observed external signals such as acoustic emission, machining forces, spindle power consumption, and vibration are related to the tool wear state. The advantage of indirect methods over direct methods is that there is no need to interrupt the process, so they can be incorporated in automated machining processes without the loss of productivity.…”

Tool Wear Monitoring for Ultrasonic Metal Welding of Lithium-Ion Batteries

“…TCM has been a popular and important research topic in manufacturing and has received tremendous attention over the past several decades. The majority of the TCM literature has been focused on machining processes [7][8][9][10][11][12][13][14][15][16][17][18][19][20] and forming processes [21][22][23][24]. Tool wear mechanism in cutting processes has been investigated in Refs.…”

“…Correlations of machining process conditions and the volumetric tool wear rate have been identified based on M-ratio in Refs. [19,20]. Tool wear monitoring techniques have been developed in Refs.…”