To investigate the tensile behavior of 40Cr steel, the specimens with varying angular distribution of bionic units were fabricated by laser. Microstructure and micro-hardness of the bionic units were detected. The micro-hardness of bionic unit was remarkably improved, which was more three times as that of the untreated specimen. Results of the tensile test demonstrated that there was a major influence on enhancing the strength and plasticity of 40Cr steel due to the existence of bionic units. Meanwhile, there was a downward trend of the yield strength (YS) and tensile strength (TS) of the specimen with the increase of angular distribution (α) of the bionic unit, but the degree of elongation (EL) improvement was enlarged. As compared with that of the untreated sample, the angular distribution (α) of the bionic unit was 0°, the yield strength (YS) as well as tensile strength (TS) of the specimen was improved by 24.77% and 20.73%, respectively. When α was 90°, the elongation (EL) of the specimen was increased by 48.98%. The relation equations of YS, TS, and EL concerning the bionic unit angular distribution were established as follows:

$y_{\mathit{YS}}=679.69672-0.69754\alpha$;

$y_{\mathit{TS}}=792.82787-0.7959\alpha$;

$y_{\mathit{EL}}=18.48187+0.07372\alpha -0.000393444{\alpha }^2$.

为了研究40Cr钢的拉伸性能，通过激光制造了具有不同仿生单元角度分布的试样。检测了仿生单元的微观结构和显微硬度。仿生单元的显微硬度显着提高，是未处理样品的三倍以上。拉伸试验的结果表明，由于存在仿生单元，对增强40Cr钢的强度和可塑性有重大影响。同时，随着仿生单元的角分布（α）的增加，样品的屈服强度（YS）和抗张强度（TS）呈下降趋势，但是伸长率（EL）的改善程度增大。与未经处理的样品相比，仿生单元的角度分布（α）为0°，样品的屈服强度（YS）和抗张强度（TS）分别提高了24.77％和20.73％。当α为90°时，样品的伸长率（EL）增加了48.98％。建立关于仿生单位角分布的YS，TS和EL的关系方程式如下：

${ÿ}_{\mathit{S}}=679.69672--0.69754\alpha$;

${ÿ}_{\mathit{TS}}=792.82787--0.7959\alpha$;

${ÿ}_{\mathit{EL}}=18.48187+0.07372\alpha --0.000393444{\alpha }^2$。