Manufacturing Processes Quiz

A built-up edge alters the rake angle of a cutting tool, which affects the chip formation process. It also influences the surface roughness of the workpiece by creating irregularities.

Wire drawing is a metal forming process that requires lubrication to reduce friction, which helps prevent wear and tear on the die and wire. The process is typically carried out at room temperature, not high temperatures, as in other processes.

A decrease in rake angle leads to an increase in the shear area, as more material is engaged in the cutting process. The shear angle also increases, and the cutting force reduces due to the increased shear area.

Flat rolling is a metal forming process where the roll diameter influences the bite, which affects the amount of reduction in thickness. Thick laminates, needing greater thickness reduction, require larger rolls. The presence of external tension influences the neutral plane's position.

The chip thickness ratio in orthogonal cutting is determined by the ratio of the original material thickness to the chip thickness. It is influenced by the rake angle, shear angle, and feed rate, but not by the clearance angle, cutting speed, or solid angle.

The ideal deformation in extrusion depends on the plastic behavior of the metal being extruded, the friction between the material and the die, the extrusion force, and the die angle. The initial and final areas of the metal part are key factors in determining deformation.

In flat rolling, the speed of the laminate changes across the rolling mill. It increases from the entrance towards the neutral plane and then decreases from the neutral plane to the exit. The speed at the neutral plane is different from the peripheral speed of the rolls, but the laminate's speed at the neutral plane is not necessarily the highest.

Extrusion is a metal forming process that typically requires lubrication to reduce friction between the metal and the die. Aluminum is extensively used in extrusion, but other metal alloys are also used. Direct extrusion generally requires higher pressures compared to indirect extrusion, but pressure doesn't significantly change throughout most of the direct extrusion process.

A reduction in strain rate generally leads to a decrease in flow stress, making the metal more ductile. It also affects the strength coefficient (K) and strength hardening exponent (n) in the Hollomon equation, but not Young's modulus.

A linear groove can be created with a shaping machine, broaching machine, and milling machine. Lathes, drilling machines, and deep drawing machines aren't typically used for creating linear grooves, but they have other specific functions.

Multiple-point cutting tools are commonly used in milling, broaching, planing, and sawing. Turning, drilling, and shaping typically employ single-point tools.

Processes like rolling, thread rolling, coining, trimming, and planing are not chip removal operations. These processes shape the metal by applying pressure, unlike machining processes that remove material.

Upsetting is a forging process where the dies are typically flat, and the pressure distribution is uneven. The pressure is highest at the lateral sides and decreases towards the middle of the part. Friction plays a role, but the pressure doesn't reduce with increasing friction.

The maximum draft (thickness reduction) in flat rolling is primarily determined by the friction coefficient between the rolls and workpiece. The position of the neutral plane, initial thickness, and rotational speed of rolls also affect the process, but the main factor is friction.

A roughing operation in machining involves using lower cutting speeds but higher feed rates and depths of cut to remove a significant amount of material quickly. This approach prioritizes material removal over surface finish.

A shaping operation involves a single point tool moving linearly past a stationary workpart, creating a flat surface. This differs from other machining processes that use multi-point tools or rotational movement.

The maximum drawing reduction in wire drawing, under ideal conditions (no friction, only strain hardening), is directly determined by the strain hardening exponent of the material. Higher strain hardening exponents allow for greater reduction per draw without cracking.

Locked and counterlocked dies are commonly used in impression die forging. This technique helps control the metal flow and prevent defects by providing a more even and controlled pressure distribution.

Open-die forging is closely related to upsetting, fullering, and cogging. These processes use open dies, allowing for flexibility in shaping the metal.

Facing operations, which involve creating a flat surface on a workpart, are typically performed using a lathe. Lathes are designed for manipulating a workpiece with a rotating cutting tool, making them ideal for facing operations.

In the orthogonal cutting model, the chip thickness ratio is defined as the ratio of the chip thickness (tc) to the original material thickness (tm). It reflects the amount of material removed during the cutting operation.

In a single-edged cutting tool, the physically measurable forces are the cutting force and the thrust force. The cutting force is exerted in the cutting direction, while the thrust force is perpendicular to it, pushing the tool against the workpiece.

In tensile testing, engineering stress is always lower than true stress, even before necking. This is because engineering stress is based on the original cross-sectional area, which decreases as the sample elongates. True stress, calculated using the instantaneous cross-sectional area, accounts for this reduction.

Milling operations utilize a multi-point cutting tool that rotates to remove material. End milling involves the cutter overhanging the work on one side, while face milling utilizes a horizontal knee-and-coloumn milling machine. In conventional milling, the cutter and feed directions are aligned, while in climb milling they are opposite.

Threaded parts can be produced using several manufacturing processes, including turning, broaching, shaping, rolling, and drawing. Each process has its unique characteristics and advantages for creating threads.

Merchant-Ernst theory and Pijspanen’s theory both analyze cutting processes, but their approaches differ. Merchant-Ernst focuses on the shear motion of the chip, while Pijspanen considers the frictional forces at the cutting face. Both theories have significant contributions to understanding chip formation.

In chip removal machining operations, material undergoes plastic deformation, resulting in a change in shape and a decrease in hardness compared to the base material. There's no purely elastic deformation involved in this process.

Taylor's law, a critical relationship in tool life, is applicable to various cutting operations, including turning, milling, and drilling. It focuses on the relationship between cutting speed and tool life, based on empirical observations.

The built-up edge, a layer of deformed metal on the tool's cutting edge, alters the rake angle, affecting chip formation and surface finish. It can also impact other aspects of the cutting process.

Taylor's law constants, n and C, are determined by plotting experimental data of flank wear against time and cutting speed. This data provides a graphical relationship between tool life and cutting conditions.

Reducing strain rate during cold forming generally decreases flow stress and increases ductility, making the metal moreformable. This effect is observed in the Hollomon equation, where changing the strain rate influences the plastic flow stress of the material.

Increasing the strain rate during cold forming generally increases the plastic flow stress, making the metal more difficult to deform and reducing its ductility. As strain rate increases, the metal becomes more resistant to deformation.

The built-up edge, a layer of deformed material on the tool's cutting edge, is the primary factor affecting the rake angle. It changes the cutting edge geometry and influences the chip formation process.

Increasing the temperature during cold deformation tends to decrease the plastic flow stress and reduce the metal's ductility. While the temperature doesn't significantly affect Young's modulus, it significantly impacts the metal's resistance to deformation and its ability to stretch before breaking.