This work provides the description of an experimental study for assessing the hardness of metallic test samples, subjected to the Jominy End-Quench Hardenability Test, by employing typical microhardness tests. Additionally, experimental measurements of the propagation velocity of ultrasound in the test samples were correlated with the microhardness results. A systematic protocol is presented for undergraduate mechanical engineering lectures, addressing the development of experiments, including the sorting and analysis of the resulting data; also, its impact on the expected competencies and abilities of the students is discussed. Several test samples of AISI 4140 steel were used for three experimental sets: heat-treated with the Jominy End-Quench Hardenability Test, fully tempered, and non-treated samples. All samples were evaluated by using typical microhardness tests and ultrasonic pulse-echo measurements to quantify their hardness at multiple locations. The proposed methodology not only strengthened some of the different required abilities of engineering students but also introduces a new procedure, using ultrasonic signals, to estimate hardness in undergraduate programs. The obtained results show a significant correlation between the experimental data from microhardness and ultrasonic measurements, with a maximum precision of -96.36% (inverse correlation) within the studied range. A discussion is provided regarding the means of improving the skills of undergraduate students in the course of Material Science, including experimental mechanical testing abilities through these systematic methods.

这项工作描述了一项实验研究，用于通过采用典型的显微硬度测试来评估金属测试样品的硬度，这些样品经过端部淬火淬透性测试。此外，测试样品中超声波传播速度的实验测量与显微硬度结果相关。为本科生机械工程讲座提出了一个系统协议，解决实验的发展，包括结果数据的排序和分析；此外，还讨论了它对学生预期能力和能力的影响。AISI 4140 钢的多个测试样品用于三个实验组：经过端部淬火淬透性测试热处理的样品、完全回火的样品和未经处理的样品。所有样品均使用典型的显微硬度测试和超声波脉冲回波测量进行评估，以量化其多个位置的硬度。所提出的方法不仅增强了工程专业学生所需的一些不同能力，而且还引入了一种使用超声波信号来估计本科课程硬度的新程序。所得结果表明显微硬度和超声测量的实验数据之间存在显着相关性，在研究范围内的最大精度为-96.36%（逆相关）。讨论了如何通过这些系统方法提高本科生材料科学课程的技能，包括实验机械测试能力。