Introduction

Introduction:

Design-and-Make Assignment 1 - heat-treatment effects and punch/chisel manufacturing.

In this assignment, we had to design and manufacture two engineering hand tools, a cold chisel and centre-punch.

Before that, we observed carefully the process of the heat treatment known as hardening and tempering to change the mechanical properties of the samples.

Conduct hardness tests before and after heat treatment to determine which of the materials was suitable for the tools to be made.

• For Hardness test 1, using the Hardometer instruments, we determined the Vickers Hardness for each of the three samples. Looked up the Vickers Hardness using the instrument's 30kgf diamond-point table, we recoded both the indentation value and the corresponding Vickers Hardness.
• For Heat treatment 1- hardening and tempering, we heat all of the three samples to a critical temperature before quenching rapidly in water, then re-heat again and quenching in oil to remove any brittleness and tendency to crack, chip or splinter.
• For Hardness test 2, we repeated the Hardometer tests, again and recoded the indentation values and corresponding Vickers Hardness.