Grinding Technology (Week 10)

Question 1

What are Abrasive Materials?

Answer 1

Abrasive materials are hard crystals/substances that are either found in nature or manufactured. The most used materials are Aluminum oxide, Silicon carbide, Cubic boron nitride, and Diamond.

Question 2

What is Grinding?

Answer 2

Grinding is a surface finishing process that uses hard abrasive particles to remove a very thin layer of material to show a high surface, shape, and dimension quality.

Question 3

What are 4 material types of Abrasives?

Answer 3

1. Aluminum Oxide
2. Silicon Carbide
3. Diamond Wheels
4. Cubic Boron Nitride (CBN)

Question 4

What are Aluminum Oxide Wheels used for?

Answer 4

Is used for high tensile- strength materials, such as machine steels, alloy steels, high-carbon steels, and tough bronzes.

Question 5

What are Silicon Carbide Wheels used for?

Answer 5

Is used for low-tensile-strength materials, such as cast iron, aluminum, brass, copper, glass, and plastics.

Question 6

What are Diamond Wheels used for?

Answer 6

Are used for grinding cemented carbides and hard vitreous materials, such as glass and ceramics.

Question 7

What are Cubic Boron Nitride (CBN) Wheels used for?

Answer 7

Is used for grinding end mills, milling cutters, and a variety of hardened cutting tools. Also, it is a superior material for the high-speed grinding of woodworking tools

Question 8

What are 4 applications for abrasives?

Answer 8

1. Grinding wheel
2. Grinding stone
3. Sandpaper
4. Sandblasting media

Question 9

Abrasive Operations
All abrasive operations can be considered as material removal processes with geometrically undefined cutting edges. Each abrasive grain acts like a __________________ with _____________________.

Answer 9

Abrasive Operations
All abrasive operations can be considered as material removal processes with geometrically undefined cutting edges. Each abrasive grain acts like a [single cutting tool] with [undefined geometry].

Question 10

What are the 3 main parts or elements of a Grinding Wheel?

Answer 10

1. Bonds/Binding Agent
2. Pores/Void
3. Abrasive grain

Question 11

What are the 5 specifications on a grinding wheel eg.
1 14192 250x25x25 51-A-36-L-5-V-23 40m/s

Answer 11

1 = Geometry

14192 = Product Number

250x25x25 = Dimensions

51-A-36-L-5-V-23 = Composition

40m/s = Max SPEED

Question 12

What is the standard marking system for Aluminum oxide and silicon carbide wheels? eg.
51 A 36 L 5 V 23

Answer 12

51 = Prefix

A = Abrasive Type

36 = Grain Size

L = Grade

5 = Structure

V = Bond Type

23 = Manufacturer’s Record

Question 13

What are the 2 common types of grinding machines?

Answer 13

1. Flat or surface grinding
   * It is used to remove material from flat surfaces.
   * Spindle position can be horizontal or vertical.
   * Surface finish (Ra) ~0,15 – 0,6 μm
2. Cylindrical grinding
   * It is used to remove external or internal cylindrical surfaces.
   * It is also known as Universal grinding.
   * The workpiece is usually held in a rotating chuck in the headstock or between centers.
   * The wheel rotates at very high rotational speed (N).
   * Surface finish (Ra) ~ 0,8 – 1,6 μm

Question 14

What wheel should be selected for grinding Cemented Carbide?

Answer 14

A diamond wheel

Question 15

What wheel should be selected for grinding Machine Steel?

Answer 15

An aluminum oxide wheel

Question 16

What wheel should be selected for grinding Cast Iron?

Answer 16

A silicon carbide wheel