Differential scanning calorimetry (DSC) provides easy screening for thermal hazard evaluation. Here, we investigate the difference between using glass and stainless-steel vessels on the DSC measurement of exothermic d...Differential scanning calorimetry (DSC) provides easy screening for thermal hazard evaluation. Here, we investigate the difference between using glass and stainless-steel vessels on the DSC measurement of exothermic decomposition energy (QDSC) for 41 chemical substances (containing nitro, halogen, peroxide, and sulfur groups, and hydrazine bonds). Two borosilicate glass vessels (capillary and ampule) and one stainless-steel vessel were used. All QDSC values obtained were investigated with reference to the permissible fluctuation range specified by the ASTM (American Society for Testing and Materials) international Both glass vessels produced very similar QDSC values, despite different sample scales. The QDSC values obtained with the glass vessels were generally roughly within the variation tolerance range of the stainless-steel vessel. Notable exceptions were halogen- or sulfur-containing compounds;these exhibited smaller QDSC values with glass vessels in almost all cases. We will investigate whether certain structures in compounds react with stainless steel. The vessel material choice is crucial in evaluating the true reactivity of a substance.展开更多
Spectrally selective glazing system attracts great attention for energy efficient radiator applications. The present work reports the possibility of a specific shield (Stainless steel/Borosilicate glass) to provide pa...Spectrally selective glazing system attracts great attention for energy efficient radiator applications. The present work reports the possibility of a specific shield (Stainless steel/Borosilicate glass) to provide passive cooling for the purpose of reducing the use of classical active method. Radiative cooling devices require a convective shield that blocks all incoming solar radiation, but should selectively reemit radiation in the “atmospheric-window” region. In this study, borosilicate glass substrate coated with a stainless steel thin film was prepared by thermal evaporation and low pressure (6.3 × 10<sup>-3</sup> bar) DC plasma sputtering, in order to achieve the radiative cooling effect. The optical properties of the optimal thickness thin film were measured in the wavelength range of 0.3-20 μm by an OL-750 double-beam spectroradiometer. The thin film has high visible band reflectance with high infrared band emissivity across the full 8-13 μm;which indicates that stainless steel thin film can be used as good radiative cooling material.展开更多
A novel buckling-induced forming method is proposed to produce metal bellows.The tube billet is firstly treated by local heating and cooling,and the axial loading is applied on both ends of the tube,then the buckling ...A novel buckling-induced forming method is proposed to produce metal bellows.The tube billet is firstly treated by local heating and cooling,and the axial loading is applied on both ends of the tube,then the buckling occurs at the designated position and forms a convolution.In this paper,a forming apparatus is designed and developed to produce both discontinuous and continuous bellows of 304 stainless steel,and their characteristics are discussed respectively.Furthermore,the influences of process parameters and geometric parameters on the final convolution profile are deeply studied based on FEM analysis.The results suggest that the steel bellows fabricated by the presented buckling-induced forming method have a uniform shape and no obvious reduction of wall thickness.Meanwhile,the forming force required in the process is quite small.展开更多
In order to enhance the ablation-resistant performance of stainless-steel conductive rails,Mo coating,410 stainless steel coating and 15 wt%Cr_(2)AlIC particles reinforced 410 stainless steel composite coating were pr...In order to enhance the ablation-resistant performance of stainless-steel conductive rails,Mo coating,410 stainless steel coating and 15 wt%Cr_(2)AlIC particles reinforced 410 stainless steel composite coating were prepared and evaluated.Different from the weak interfacial strength caused by the dissimilar metals between Mo and steel rails,410 stainless steel coating has better interfacial contact with steel rails.The introduction of Cr_(2)AlC into 410 stainless steels further strengthened the mechanical properties of coating by alloy strengthening effect and particle strengthening effect,as the decomposition of Cr_(2)AlC into nano CrC particles is accompanied with the diffusion of Al atoms into 410 stainless steels.It was found that the composite coating can still resist arc erosion at 150 A current,as a dense oxide film formed during the ablation process and the decomposition of Cr_(2)AlC contributed to the heat absorption.展开更多
文摘Differential scanning calorimetry (DSC) provides easy screening for thermal hazard evaluation. Here, we investigate the difference between using glass and stainless-steel vessels on the DSC measurement of exothermic decomposition energy (QDSC) for 41 chemical substances (containing nitro, halogen, peroxide, and sulfur groups, and hydrazine bonds). Two borosilicate glass vessels (capillary and ampule) and one stainless-steel vessel were used. All QDSC values obtained were investigated with reference to the permissible fluctuation range specified by the ASTM (American Society for Testing and Materials) international Both glass vessels produced very similar QDSC values, despite different sample scales. The QDSC values obtained with the glass vessels were generally roughly within the variation tolerance range of the stainless-steel vessel. Notable exceptions were halogen- or sulfur-containing compounds;these exhibited smaller QDSC values with glass vessels in almost all cases. We will investigate whether certain structures in compounds react with stainless steel. The vessel material choice is crucial in evaluating the true reactivity of a substance.
文摘Spectrally selective glazing system attracts great attention for energy efficient radiator applications. The present work reports the possibility of a specific shield (Stainless steel/Borosilicate glass) to provide passive cooling for the purpose of reducing the use of classical active method. Radiative cooling devices require a convective shield that blocks all incoming solar radiation, but should selectively reemit radiation in the “atmospheric-window” region. In this study, borosilicate glass substrate coated with a stainless steel thin film was prepared by thermal evaporation and low pressure (6.3 × 10<sup>-3</sup> bar) DC plasma sputtering, in order to achieve the radiative cooling effect. The optical properties of the optimal thickness thin film were measured in the wavelength range of 0.3-20 μm by an OL-750 double-beam spectroradiometer. The thin film has high visible band reflectance with high infrared band emissivity across the full 8-13 μm;which indicates that stainless steel thin film can be used as good radiative cooling material.
基金National Natural Science Foundation of China(Grant No.52175349)Aeronautical Science Foundation of China(Grant No.20200009057004)。
文摘A novel buckling-induced forming method is proposed to produce metal bellows.The tube billet is firstly treated by local heating and cooling,and the axial loading is applied on both ends of the tube,then the buckling occurs at the designated position and forms a convolution.In this paper,a forming apparatus is designed and developed to produce both discontinuous and continuous bellows of 304 stainless steel,and their characteristics are discussed respectively.Furthermore,the influences of process parameters and geometric parameters on the final convolution profile are deeply studied based on FEM analysis.The results suggest that the steel bellows fabricated by the presented buckling-induced forming method have a uniform shape and no obvious reduction of wall thickness.Meanwhile,the forming force required in the process is quite small.
基金supported by Beijing Natural Science Foundation(3232011)the Pre-Research Program in National 14th Five-Year Plan(80923010304)the National Natural Science Foundation of China(52130509).
文摘In order to enhance the ablation-resistant performance of stainless-steel conductive rails,Mo coating,410 stainless steel coating and 15 wt%Cr_(2)AlIC particles reinforced 410 stainless steel composite coating were prepared and evaluated.Different from the weak interfacial strength caused by the dissimilar metals between Mo and steel rails,410 stainless steel coating has better interfacial contact with steel rails.The introduction of Cr_(2)AlC into 410 stainless steels further strengthened the mechanical properties of coating by alloy strengthening effect and particle strengthening effect,as the decomposition of Cr_(2)AlC into nano CrC particles is accompanied with the diffusion of Al atoms into 410 stainless steels.It was found that the composite coating can still resist arc erosion at 150 A current,as a dense oxide film formed during the ablation process and the decomposition of Cr_(2)AlC contributed to the heat absorption.
