Specimen size effect on the strength of nickel-boron alloys

[Display omitted] •The strength of electrodeposited Ni-B alloys is evaluated by micro-compression.•Three types of the deformation behavior are confirmed in different Ni-B alloys.•A small-is-stronger specimen size effect is confirmed.•The flaw-sensitivity is evaluated by Weibull statistics. Nickel-boron alloys are prepared by an electrodeposition method. The as-deposited nickel-boron alloy is then annealed at 250 °C and 400 °C for 4 h. Their mechanical strengths and specimen size effects on the strength are evaluated by micro-compression test using pillar-type micro-specimens fabricated by focused ion beam system. In all as-deposited and annealed specimens, a smaller-is-stronger specimen size effect is confirmed. The compressive strength of the nickel-boron alloys reaches a maximum of 5.79 GPa with the smallest specimen size in this work.