الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 73 |  |  |
| | | from | 73 | | |
Abstract
In the present investigation, holes in AA7075 aluminum sheets were drilled
using friction drilling method. The effect of the tool rotational speed (spindle speed) and the tool conical angle on the hole dimensions were investigated. The friction drilling process was performed using tool rotational speeds of 3100 rpm, 3400 rpm
and 3700 rpm. The tool conical region has hexagonal shape with conical angles of 25o , 30o and 35o
. To evaluate the quality of the manufactured holes, the hole
diameter, bushing height and wall thickness dimensions were measured. The
analysis of variance (ANOVA) statistical method was used to evaluate the influence of the spindle speed and the conical angle. Moreover, models were developed using regression analysis technique to predict the hole dimensions. The results revealed that the maximum average busing height was about 7.945 mm exhibited by holes friction drilled using rotational speed and conical angle of 3700 rpm and 30o
, respectively. While the maximum average busing wall thickness
was about 1.325 mm exhibited by holes friction drilled using rotational speed and conical angle of 3700 rpm and 25o
, respectively. The maximum hole diameter was 15.17 mm for a hole drilled using spindle speed and conical angle of 3100 rpm and 30o
, respectively. Furthermore, the minimum hole diameter was about 15 mm for a hole friction drilled using tool spindle speed and conical angle of 3400 rpm and 30o , respectively.
The ANOVA results showed that the influence of the spindle speed and
conical angle on the hole diameter, bushing height and bushing wall thickness is not significant. The developed regression models have acceptable accuracy. The
regression models for hole diameter, bushing height and bushing wall thickness exhibited R2 values of 0.966, 0.866 and 0.740, respectively.