Burrs formed by milling are three-dimensional in nature. Therefore the three-dimensional effects on milling burr formation in 304L stainless steel were considered. An important aspect of the three-dimensional effects is the exit order of the tool edges because the burr remains near the final exit position of the tool along the workpiece edge. The geometric parameters of the workpiece and tools were varied to change exit order in the workpiece around the cutting edge. Moreover in this paper, classification of milling burrs based on burr location, shape and mechanism is also proposed to avoid confusion. The milling burrs were classified according to three locations, five shapes and four burr formation mechanisms based on fractography. The exit burr on the exit surface and the side burr on transition surface of workpiece were mainly analyzed. The effect of in-plane exit angle and radial rake angle on burr formation were shown and the burr formation mechanism for each burr was also discussed.

To prevent problems caused by burrs in machining, reduction and control of burr size is desirable. This paper presents a basic framework for and conceptual understanding of the burr formation process based upon the material properties of the workpiece. In order to verify this framework and explain the basic phenomena in the burr formation process, the deformation at the edge of the workpiece was analyzed using a finite element method (FEM). Micro-machining tests under an optical microscope and a scanning electron microscope using AI-2024-O material were also done to observe the burr formation process. The feed rate and tool edge radius were varied and the resulting burr formation observed. FEM analysis of burr formation in the 2024 material and observation of the deformation at the workpiece edge in the micromachining tests verified the proposed conceptual understanding of the burr formation process. For the experimental conditions examined, all of the burrs in AI-2024-O were "negative" burrs, that is, edge breakout. As the feed was increased two effects were observed. One effect was an increase in the resulting burr thickness. Another effect, which was observed during the burr initiation stage while machining with a sharp tool, was an increase in both the distance and depth of the initial pivoting point of the burr from the tool edge.

Three discrete binuclear gadolinium(III)–copper(II) complexes (CuGd(fsadien)NO3·5H2O (1), CuGd(hsapn)NO3·3H2O (2), and [Gd(pvm)3Cu(A)] (3)) have been synthesized; we use the notation H4fsadien=N,N′-bis(3-carboxysalicylidene)diethylenetriamine, H4hsapn=N,N′-bis(3-hydroxysalicylidene)-1,2-propanediamine, Hpvm=dipivaloylmethane (2,2,6,6-tetramethyl-3,5-heptanedione), and H2A=4-(6-methyl-8-oxo-2,5-diazanona-1,5,7-trienyl)imidazole. Magnetic susceptibility measurements (4.2–300 K) have revealed that the spin coupling between the Gd(III) and Cu(II) ions is ferromagnetic with coupling constants J=+2.3 cm−1 for (1), +5.7 cm−1 for (2), and +0.5cm  −1 for (3), on the basis of the spin-Hamiltonian H=−2JSGd·SCu.

The mechanical material removal (MRR) mechanisms in lapping were investigated, using concepts of two-body vs. three-body abrasion and ductile vs. brittle machining. The statistical nature of the depth of cut in the lapping process was described using distribution of abrasive sizes in the slurry. Through the change in abrasive size distribution, the time dependent characteristic of MRR was captured in the model. Experiments were conducted for model verification. It was found that a constant 60 deg effective inclusion angle allowed the model to fit measurement well. [S1087-1357(00)00504-9]

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