一般投稿
くぼみ寸法形状から推定した微小球反発硬さeNM3A10の衝撃荷重
2022 年 67 巻 4 号 p. 136-139
詳細
2022 年 67 巻 4 号 p. 136-139
In the Small ball Rebound Hardness eNM3A10tester, an alumina ball indenter with a diameter of
3mm and a mass of approximately0．056g is ejected at a velocity of V1＝10m／s. The rebound velocity V2of the ball indenter after impacting the sample is measured to obtain the rebound coefficient e ＝V2／V1, which is used as an index of rebound hardness. In general, in the rebound hardness test, the kinetic energy of the indenter impacting the specimen is constant, but the load due to the impact varies depending on the hardness of the specimen. We investigated experimentally that how much load is generated during the impact, using high-precision hardness reference blocks and a static hardness tester. It is confirmed that the impact load is greater for harder specimens and is less than
50kgf for metal specimens with hardness less than700HV. The estimated time of deformation is less
than0．1ms.
