共查询到20条相似文献,搜索用时 93 毫秒
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为了研究不同老化时间和温度对橡胶表面力学性能的影响,通过纳米压痕仪测量了老化前后以及不同老化时间和温度下橡胶的弹性模量、硬度、储能模量、损失模量和损耗因子.研究结果表明,老化时间和温度是影响橡胶表面纳米力学性能的2个关键因素,且相比于老化时间,老化温度对橡胶力学性能的影响更为显著;在90℃和105℃老化温度下,橡胶的弹性模量、硬度、损耗因子等力学性能受老化时间的影响较小;在120℃以上,随着老化时间的延长,橡胶的硬度、弹性模量逐渐增大,蠕变性能与黏性逐渐减弱;在135℃时,其力学性能呈现先快后慢的变化模式,老化3d之后,其硬度与弹性模量开始迅速增大,后期变化速率逐渐减小.在工程上,对于长期服役于较高温度下的密封件来说须严格控制其服役温度,以达到防止密封件老化、提高密封寿命的目的 . 相似文献
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在分析布氏硬度试验压痕图像的基础上,提出了基于数字图像处理的布氏硬度压痕直径测量方法.利用CCD相机获取压痕图像,通过图像分割、目标区域处理、压痕圆拟合等步骤完成图像处理,由此实现对压痕尺寸的自动精确测量. 相似文献
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The Shore hardness is still used as a characteristic property for elastomers. Rubber compounds with a hardness of 60 Shore A are often used for vibration insulation elements. The hardness of pneumatic seals lies in the range of 80 Shore A, and for hydraulics it is around 95 Shore A. The hardness of a rubber compound is fine-tuned by the filler content. With increasing filler content, usually carbon black, the hardness and thus the stiffness of the rubber compound increases. Industrial rubber manufacturers often accept a tolerance within ±3 Shore A. This value practically seems low and is therefore often accepted by the end-users. The effect of this tolerance on the application properties is investigated on the example of an acrylonitrile-butadiene rubber compound with a Shore hardness of 60 Shore A and samples with hardness of plus and minus 3 Shore A. Results of tensile tests and dynamic mechanical thermal analysis show that even such small deviation from the nominal value has a significant influence on material stiffness and damping performance over the entire application temperature range. Vibration tests by means of a shaker up to 700 Hz also prove a large variation in vibration transmission behaviour of a vibration de-coupler due to the rubber compound tolerance. 相似文献
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É. G. Aslanyan 《Measurement Techniques》2005,48(1):57-63
Information on the developed and improved State Standards of hardness is presented. New standard technical documentation on methods and instruments for measuring hardness is described, and the results of international key comparisons of the standards are presented. The concept of calculating the uncertainty of the results of hardness measurements is put forward and modern developments in the field of portable hardness meters are described.Translated from Izmeritelnaya Tekhnika, No. 1, pp. 45–50, January, 2005. 相似文献
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结合基建现场利用里氏硬度计测量过程中存在误差的情况,介绍里氏硬度计的测量原理,分析影响里氏硬度计的测量结果的误差,并提出相应措施。 相似文献
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Local stress and strain variations in the deformation zone can be ascertained by measuring hardness. Hardness is correlated
with strain and stress. The expressions discussed later are useful in determining the local variations in stress and strain
from hardness measurement. It is a simple method compared to visioplasticity. One can estimate the forces required for a forming
process. It helps in the choice of equipment, design of tooling and selection of lubricant for the particular process. 相似文献
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应用微观形貌、显微硬度和声发射技术对石钢丝表面的磷化层进行了分析和测定,发现磷化层的质量与微观组织、显微硬度值和声发现信号特征有着很好的对应关系。这三种试验数据可作为磷化层质量评估的判据。 相似文献
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对金属洛氏硬度测量中合成不确定度和扩展不确定度的分析与计算及在洛氏硬度测量中的实践应用进行了阐述。该方法对金属洛氏硬度的测量不确定度评定有一定的参考价值。 相似文献
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测定了离子束辅助沉积TiN,CrN薄膜的纳米压入硬度(Hnano值)、维氏显微硬度(Hv值)和努氏显微硬度(HK值)。结果发现,HK值比Hv值更接近于Hnano值,相对较为准确。膜的厚度(t)越薄,三种方法测得硬度值差别越大;膜的厚度越厚,差别越小。随着膜的厚度增加,Hk值和Hv值逐渐接近Hnano值。t≈5.0μm时,Hv≈HK≈Hnano对于硬膜软基体模型,如果膜厚〉5.0μm,可以采用显微硬度计较为准确地测量薄膜硬度;膜厚〈5.0μm时,应避免使用显微硬度法而采用纳米压入法。 相似文献
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提出了一种基于预多频涡流检测技术的钢球硬度分选系统,介绍了系统组成、工作原理及硬软件设计。该系统以工业控制PC机为核心,采用8个频率工作,通过对每个频率的测量信号的综合评价,可确定钢球的硬度。试验和实际生产应用均证明该系统可对钢球硬度进行100%自动分选,且灵敏度高,可靠性好。 相似文献