Drill Hole Orientation: Its Role and Importance on the Compression Response of Pure Magnesium

Abstract

Drilling is used in creating cylindrical through-holes for various applications. While optimizing drilling parameters is widespread, the effect of a drilled through-hole on the structural stability of components is not fully documented. The base material, along with other parameters, such as drill diameter, drill location and its orientation affect structural stability. Since carrying out tests on different base materials can be time consuming, simulation software can instead be used to provide valuable information. However, the comparison between experiments and simulations gets difficult; hence, this study attempts to provide a basis for effective comparison by studying simulations and compression tests, comparing the two, and documenting the role of drill hole orientation on the compressive response of magnesium, a material with immense potential in light-weight components. Simulations and experiments were carried out on three through-hole orientations and were compared to the undrilled scenario. Results demonstrate significant differences in compression behaviour. While the compressive yield strength increased in all three drill orientations, ultimate strength and ductility was reduced in horizontal and angular drill hole orientations. These observations, therefore, provide valuable insight into choosing the right orientation for different applications.

Strength enhancement and retention in magnesium subjected to uniaxial compression using centralized partial drill holes

“…In addition, table 2 concluded that for a drill depth of 1.5 mm, 1 mm and 1.5 mm drill diameters provided the best results. Further, previous studies [15,16] also emphasized on the better performance of the 1.5 mm vertical drill hole. Hence, with a 1.5 mm drill hole diameter and 1.5 mm drill depth, a study was conducted on square shaped holes as well as a hexagon shaped holes as shown in figure 3.…”

“…Five samples per orientation were tested to arrive at the stress-strain behaviour. The results of this study were compared with previous studies [15,16] where samples with no drill and through hole drills were done. All manufacturing parameters, compression testing parameters were kept consistent with previous research [15][16][17] to enable oneto-one comparisons.…”

“…Since circular sensors come in different dimensions, for the purpose of this work, two different drilling scenarios were considered for the holes to fit the sensors in. Based on previous studies [15,16], where a 1.5 mm diameter drill hole provided optimum results, here too, using a constant drill hole diameter of 1.5 mm, the effect of change in drill depths were assessed in the first scenario. For this, drill depths of 1 mm, 1.5 mm, 2 mm, 2.5 mm were considered.…”

“…Having done the experiments, a curious question arose as to whether the behaviour would change if the hole was to be in the shape of a square or a hexagon. Using material properties from monolithic magnesium of previous studies [15,16], simulations were carried out in ANSYS v20.…”

“…There have been several strides made to further lightweight magnesium alloys. This was done by using syntactic foams as well as using controlled defects [4,[14][15][16][17].…”