scholarly journals Discussion: “Fracture and Wear as Factors Affecting Stochastic Tool-Life Models and Machining Economics” (Rossetto, S., and Levi, R., 1977, ASME J. Eng. Ind., 99, pp. 281–286)

1977 ◽  
Vol 99 (2) ◽  
pp. 508-508
Author(s):  
L. A. Kendall
2010 ◽  
Vol 37-38 ◽  
pp. 1457-1461 ◽  
Author(s):  
Zhao Peng Hao ◽  
D. Gao ◽  
R.D. Han

Nickel-based super alloy GH4169 has been widely used in aerospace industry because of its good mechanical properties under high temperature. However, it is difficult to machine for its high strength, poor thermal conductivity and serious work-hardening. The effects of tool geometric parameters on tool life are studied by machining experiments using YG8 tools with different cutting edge angle in this paper. The tool with cutting edge angle 45°has longer tool life than 75°. The cutting experiments have been carried out using TiAlN (PVD) coated tools (AC520U) with different rake angle. It shows that the tool life with rake angle 9° were increased by 50% and 25% compared to tool with rake angle 3°and 6° when cutting speed is 30m/min. The tool with rake angle 9° is not suitable for cutting GH4169 when cutting speed is more than 35m/min. The results show that geometric parameter of cutting tool is one of the important factors affecting tool life.


1977 ◽  
Vol 99 (1) ◽  
pp. 281-286 ◽  
Author(s):  
S. Rossetto ◽  
R. Levi

Under production conditions cutting tools often fail under several failure modes, the occurrence of a single one only for a given operation being rather exceptional. In light of this observation a stochastic model is developed, considering as causes of tool failure both wear and fracture processes. Machining economics are then analyzed with a probabilistic approach, deriving distribution functions of profit rate.


1996 ◽  
Vol 118 (4) ◽  
pp. 658-663 ◽  
Author(s):  
E. Iakovou ◽  
C. M. Ip ◽  
C. Koulamas

Optimization of the economics of machining comprises the determination of the optimal cutting speed and tool replacement policy. A necessary input to the above approach is knowledge of the parameters of the tool life equation which links tool life to cutting speed. In reality, these parameters are not known and should be estimated based on actual machining data. This paper addresses the above optimization problem in the framework of an adaptive control policy. Replacement times in one production run are used to estimate the mean-time-to-failure of a tool, which is in turn used in a regression model to update estimators of the tool life parameters. Using the newly updated estimates a new cutting speed and preventive replacement policy are then determined for the next production run. The end result is an easily implementable decision making tool which can aid in the continuous improvement of the machining process.


1959 ◽  
Vol 81 (3) ◽  
pp. 239-249 ◽  
Author(s):  
Bertil N. Colding

In Part 1 of this paper, two tool-life equations are derived, one limited equation and one general tool-life equation, between the variables cutting speed, chip equivalent, and tool life. The chip equivalent, introduced by Woxén, is a well-defined function of feed, depth of cut, nose radius, and side-cutting-edge angle. The limited equation takes into account the variation of Taylor’s exponent n with the value of the chip equivalent, but the equation is only valid within certain limits of cutting speed and chip equivalent. A general equation is then derived on the basis of the limited equation. In Part 2 an expression called the productivity is derived. This relationship is valid for either maximum production or minimum cost and, combined with the general, hyperbolic, tool-life equation, it is used to investigate the optimum combination of tool-life, cutting speed, and chip equivalent.


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