The Study of Green Compression Strength of a Green Sand Mould Using Statistical Approach

Aondona Paul Ihom,Aniekan Offiong

doi:10.4236/msa.2014.512089

Abstract

The study of green compression strength of a green sand mould using statistical approach has been undertaken. Empirically generated data in National Metallurgical Development Centre, Jos Sand Testing Laboratory were used for the study. Coefficient of correlation, coefficients of determination and coefficient of multiple determinations were used to explain the relationship existing between the two independent variables of clay and moisture content and green compression strength, the dependent variable. The study showed that the coefficient of determination for Ys: X1 was 0.88 while the coefficient of correlation was 0.94, coefficient of determination for Ys: X2 was 0.90 while the coefficient of correlation was 0.95 and the coefficient of multiple determination was 0.72; these coefficients assisted tremendously in the study of green compression strength. A mathematical model was developed for the prediction of green compression strength; it was tested and proved to be a good estimation tool for estimating green compression strength values on the foundry shop floor. The study has clearly shown that statistical approach is a good tool for studying green compression strength of green sand moulds.

Highlights

Jain [1] in his work said that “the green compression strength of a green sand mould depends on grain size, shape and distribution of sand grains, type and amount of clay or other binder and moisture content”
The study of green compression strength of a green sand mould using statistical approach has been successfully carried out and the following conclusions are from the study: 1) Statistical approach has been found to be a good method of studying green compression strength of green sand mould
3) The study has shown the positive strong relationship that exists between green compression strength of the dependent variable and the two independent variables of clay content and moisture content

Summary

Introduction

Jain [1] in his work said that “the green compression strength of a green sand mould depends on grain size, shape and distribution of sand grains, type and amount of clay or other binder and moisture content”. Jain [1] tried to assess the combined effect of grain size variation and moisture content on green compression strength of green sand mould. He said that as moisture is increased, green compression strength increases until a point is reached where further increase leads to decrease in green compression. Low green compression strength in green moulds may result in defective and unsound casting [6] This is because there will be erosion, collapse, and damage of the mould wall and this will result in defects like rat tails, sand inclusions, incomplete molten metal flow, rough surfaces etc. This explains how important this property is in mould production and is always monitored in sand casting [4]-[7]

Objectives

Methods

Results

Discussion

Conclusion