Manufacturing And Production Technology MCQ Questions & Answers | Mechanical Engineering

Flank wear occurs on the relief (flank) face of the tool. Flank wear occurs as a result of friction between the progressively increasing contact area on the tool flank.

Grinding is a machining process that involves friction between the grinding wheel and the workpiece, which generates a significant amount of heat at the point of contact.

This high temperature causes localized thermal expansion of the grinding wheel material near the contact area, while the rest of the wheel remains relatively cool.

The uneven expansion creates thermal stresses within the wheel structure.

If these thermal stresses exceed the wheel’s tensile strength, cracks begin to develop, leading to possible wheel failure.

Grinding hard materials (Option B) increases the heat generation, but the root cause of cracking remains the excessive temperature rise.

Low wheel speed (Option C) generally reduces heat generation, so it is not a cause.

While high wheel speed (Option D) can contribute to heat and stress, the primary and most direct cause of cracking is the high temperature developed at the contact point.

Hence, the correct answer is High temperature developed at the contact of the wheel face and work.

Machining of titanium and its alloys is considered difficult due to several material-related challenges that affect cutting performance and tool life.

The primary reason is the chemical reactivity of titanium at high temperatures. During machining, the cutting zone experiences extremely high temperatures, and titanium has a strong tendency to react chemically with most cutting tool materials such as carbide or high-speed steel.

This results in welding, diffusion, and adhesion between the tool and the workpiece, causing rapid tool wear, built-up edge formation, and poor surface finish.

Additionally, titanium has a low thermal conductivity, which means heat generated during cutting does not dissipate easily. Most of this heat concentrates at the tool tip, further accelerating wear and reducing tool life.

However, the main factor making titanium machining difficult is the chemical reaction between the tool and the work material, not high thermal conductivity or low contact area.

Therefore, the correct answer is Option B: Chemical reaction between tool and work.

The angle formed by the leading edge of the land with a plane having the axis of the drill, is called Helix or rake angle The rake angle is the angle of the surface of a cutting tool tip over which the removed chips flow. The rake angle is the angle between the front or cutting face of the tool and a line perpendicular to the workpiece

The obtuse angle, included between the chisel edge and the lip as viewed from the end of a drill, is called Chisel edge angle It is the angle included between the chisel edge and lip of the twist drill when measuring on a plane normal to the axis.

Segmental Chips- It means chips become broken pieces before it departs from the cutter. It is often happened in high brittle materials, such as cast iron or bronze. Such as discontinuous chip caused by higher friction coefficient or higher soft ductile materials, it means poor cutting conditions

In Oblique cutting, cutting edge travels, making an angle with the normal of cutting edge. In oblique cutting system, the cutting edge of the tool May not clear the width of the workpiece

The velocity of tool along the tool face is known as Chip Velocity