Chapter 21 Flashcards
the angle that the tool makes with respect to a vertical from the workpiece.
Back rake angle-
where a reduced lead angle or a less round (and smaller nose radius compared to DOC) inserts maintains more axial (stiffer tool direction) orientation of Y, leading to greater stability.
Boring-
one of the seven basic machining processes in chip formation. Broach, cutting tool moves into work, and work stationary are the machine areas.
Broaching-
the most common metal cutting example due to the regeneration of surface waving. Part of self-excited vibration in machining.
Chatter-
a variation of continuous chip, often encountered in machining ductile materials.
Built-up edge (BUE) -
used to compute the shear angle. Defined as t/t_c. (page 499)
Chip ratio-
the chip has a velocity/speed V_c.
Chip velocity-
can cause the process-induced variation in the cutting force.
Cutting velocity-
used interchangeably with the term specific energy U. A material property related to shear flow stress, hardness and work hardening and is often described in a relative sense of the machinability of materials.
Cutting stiffness (k_s) -
used to machine the workpiece and is the most critical component.
Cutting tool-
the distance the tool is plunged into the surface.
Depth of cut (DOC) -
one of the 7 basic chip formation processes. A rotational multiple-edge tool process.
Drilling-
is the amount of material removed per revolution pr per pass of the tool over the workpiece.
Feed (f_r) -
what the resultant R is composed of along with the normal force N acting on the tool/chip interface contact area.
Friction force-
one of the 7 basic chip formation processes. (Discussed in chapters 23-27).
Grinding (abrasive machine) -
a stationary, power-driven machine used to cut, shape, or form materials such as metal and wood. (NOTE: this definition is from Britannica Concise Encyclopedia).
Machine tool-
the process of removing unwanted material from a metal workpiece in the form of chips (often called metal removal).
Metal cutting-
the process of milling requires two figures because it takes different forms depending upon the selection of the machine tool and the cutting tool; a multiple tooth process, has two feeds; has replaced shaping and planning
Milling-
three-dimensional geometry; the cutting edge and the cutting motion are not perpendicular to each other
Oblique machining
two dimensional geometry; done to test machining mechanics and theory; the cutting velocity vector and the cutting edges are perpendicular
Orthogonal machining
caused by a phase shift between overlapping cutting paths; a self-excited vibration that is caused by the closed -loop displacement response of the machining process
Regenerative chatter
a basic machining process in which chips are produced by a succession of small cutting edges, or teeth, arranged in a narrow line on a saw “blade”.
Sawing
the periodic response of the system to a constant input
Self-excited vibration
the work piece is fed at right angles to the cutting motion between successive strokes of the tool
Shaping
the onset of the shear process takes place along the lower boundary of the shear zone defined by the shear angle (phi)
Shear angles
can be found using sophisticated electronics and slow-motion playback
Shear velocity
depends only on the rake angle (alpha) ; expressed as cosine of alpha divided by one plus the sine of alpha
Shear strain
aka flow stress-is a material constant
Shear force
values found experimentally using orthogonal machining
Specific horsepower
primary cutting motion, which relates the velocity of the cutting tool relative to the work piece.
Speed
relates the total width of cut that can be machined to the rotational speed of the tool with a specified number of cutting edges
Stability lobe diagram
the process of machining external cylindrical and conical surfaces
Turning
the mechanism by which a process dissipates energy
Vibration
holds work pieces
work holding device
held in work holding devices
work piece
