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Materials Science in Additive Manufacturing Multi-material Ti6Al4V-B4C through L-DED

A

C

D E

Figure 8. Physical properties of the samples. (A) Compression curves of the three different samples (Ti64, Ti64-B4C, and radial composite [RC]).
(B) Individual hardness data points from the Ti64-B4C multi-material structure. (C) A table containing the mean ± variation of yield strength, elastic
modulus, and hardness values for the compositions (n = 3). (D) Optical image displaying the overall region of the hardness indents in the Ti64-B4C multi-
material structure: (1) Ti64-B4C, (2) intermixing, and (3) Ti64. (E) Optical image of the intermixing region: (left) Ti64-B4C region and (right) Ti64 region.

hardness, and wear resistance. This increase in compressive compressive loading capacity compared to the monolithic
strength was seen in both treated samples over the Ti64-B4C sample. 24
control, which exhibited a relatively similar performance. The increased hardness of the matrix material and the
Comparable studies conducted with these structures have higher concentration of B4C particles dispersed within it
reported increases and decreases in compressive strength
when using this type of build pattern. 11,12 Although both significantly increased the material’s resistance to machining
studies used two different steel alloys, the findings reported with the cemented carbide-cutting inserts typically used as
increased compressive strength of the RC structures heavy wear (Figure 7C). This is in stark contrast to the Ti64
compared to the alloy with the lowest compressive strength. control, where the cutting insert exhibited little to no wear.
Similarly, this increase in compressive strength of RC was The machinability of a material can be directly correlated
observed by adding the B4C particles to the Ti64 matrix to the material’s wear resistance, where a decrease in the
in both treated samples. Nonetheless, there was also an machinability increases the material’s wear resistance.
increase in defects in the RC samples over the monolithic This has been reported previously in wear testing of a Ti
Ti64-B4C samples. The radial structure of RC affects the matrix with a 24% volume fraction of B4C. The testing
cylinder’s strength under compressive loading, leading to a demonstrated that adding the particles decreased the
higher compressive loading capacity than the control and volume of the wear scar when using an alumina wear ball.
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possibly the Ti64-B4C sample. A better-optimized print The machinability of the samples decreased as the carbides
with fewer pores and no cracking should exhibit a higher in the treated samples were exposed on the surface of the

Volume 3 Issue 3 (2024) 9 doi: 10.36922/msam.3571