6m大容积焦炉烘炉实践与体会

介绍了 6 m大容积焦炉由冷态到转入正常加热温度的烘炉操作过程中 ,按照一定的升温曲线 ,通过对焦炉热工和炉体膨胀的科学管理 ,确保新建焦炉顺利由冷态过渡到生产状态。     

Relationship between Viscoelastic and Peeling Properties of Model Adhesives. Part 1. Cohesive Fracture

The viscoelastic and peeling properties of polybutadiene/tackifying resin compatible blends have been studied in detail. Viscoelastic properties have been described through the variations of the complex shear modulus, G*(ω), as a function of frequency, ω and peeling properties through the variations of peeling force (F) as a function of peeling rate (V).

After showing the objective character of the peeling curves obtained, the variations of the peeling force and peeling geometry have been studied as a function of volume fraction of the tackifying resin.

In this first paper, the analysis is focused on the first domain of the peeling curves, i.e. the cohesive fracture region. In this region, the peeling properties have been related to the viscoelastic properties in the terminal region of relaxation. It is shown that the longest relaxation time, τ_o, is a reducing parameter of the peeling curves, so a peeling master curve-which is independent of temperature, resin volume fraction and polymer molecular weight-may be defined. Furthermore, the variations of the test geometry as a function of peeling rate have been investigated: the variations of the radius of curvature of the aluminium foil have been analyzed with respect to the viscoelastic behavior of the adhesive, which in fact governs the test geometry.

A detailed analysis of all these features leads to a model which allows one to calculate the peeling curves in the cohesive domain from the adhesive formulation.     

三氯化铁为插入剂制备膨胀石墨

探讨了三氯化铁为插入剂的膨胀石墨的制备技术，分析了反应物与膨胀容积、硫含量之间的关系。     

Torque Transmission Capabilities of Bonded Polygonal Lap Joints for Carbon Fiber Epoxy Composites

Although carbon fiber epoxy composite materials have excellent properties for structures, the joint in composite materials often reduces the efficiency of the composite structure because the joint is often the weakest area in the composite structure.

In this paper, the effects of the adhesive thickness and the adherend surface roughness on the static and fatigue strengths of adhesively-bonded tubular polygonal lap joints have been investigated by experimental methods. The dependencies of the static and fatigue strengths on the stacking sequences of the composite adherends were observed.

From the experimental investigations, it was found that the fatigue strength of the circular adhesively-bounded joints was quite dependent on the surface roughness of the adherends and that polygonal adhesively-bonded joints had better fatigue strength characteristics than circular adhesively-bonded joints.     

陶瓷材料断裂韧性测试新技术：静态爆破剂预制裂纹的研究

准确测试陶瓷材料断裂韧性Ｋ１Ｃ的关键是预制具有原生裂纹的试样。本文以单边切口梁法测试Ｋ１Ｃ为基础，提出了一种简便而有效的陶瓷材料原生裂纹的预制方法－静态膨胀法。研究结果表明：静态膨胀法中裂纹的扩展是稳态的；通过调节影响微裂纹产生与扩展的多种因素，可以准确地控制裂纹扩展的深度，预制出合适的原生裂纹，为准确评价结构陶瓷的断裂韧性提供了一种有效可行的方法。     

热膨胀硅橡胶在复合材料成型工艺中的应用

简要介绍了热膨胀硅橡胶的性能和特点,热膨胀模成型工艺的原理,并应用其研制了复合材料制件。热膨胀硅橡胶适于制造热膨胀芯模。     

Mechanical behaviour of a combined joint composed of mechanical fastening and adhesive bonding

A study has been made of ‘combined’ joints consisting of mechanical fastening and adhesive bonding between rigid adherends. The mechanical characteristics of such ‘hybrid’ butt and lap shear joints have been derived by theoretical analysis. Results from experimental tests in combined joints giver reasonable agreement with the theoretical equations relating joint load to deformation.     

低温快烧无铅精陶釉的研制

采用高温熔融法制备了适用精陶的低温无铅熔块，并应用热膨胀分析仪、SEM等方法研究了精陶釉的光泽度、热稳定性、热膨胀系数等性能。结果表明：采用Li2O，SrO，B2O3等复合熔剂，可以制备出光泽度高，热稳定好，坯釉膨胀系数匹配，结合良好，适于低温快烧工艺的无铅精陶釉。     

Thermal Expansion Behavior of the Si3N4-Whisker-Reinforced Soda-Borosilicate Glass Matrix Composite

Thermal expansion behaviors of a Si₃N₄-whisker-reinforced sodaborosilicate glass matrix composite are studied. An abrupt increase of the coefficient of thermal expansion is observed and is attributed to formation of crystobalite in the sodaborosilicate glass matrix. This thermal expansion behavior is discussed with special reference to the phase transformation of the crystobalite.     

Thermal strain of high strength polyethylene fiber in low temperature

High strength polyethylene fiber (Toyobo, Dyneema® fiber: hereinafter abbreviated to DF) has a negative thermal expansion coefficient. Relation between fiber structure and thermal strain of DF used as reinforcement of DF reinforced plastic (DFRP) for cryogenic use was investigated. The crystallinities and orientation angles of several kinds of polyethylene fibers having different modulus from 15 to 134Gpa (herein after abbreviated to DFs) were measured by NMR and X‐ray. We obtained the parameters of the mechanical series‐parallel model composed of crystal and amorphous by crystallinity and modulus. Thermal expansion coefficients of DFs were estimated by mechanical series‐parallel model. All DFs having different modulus showed negative thermal expansion coefficients in the temperature range from 180 to 300K, and absolute values of those markedly increased by increasing tensile modulus of DF. The estimated thermal expansion coefficients showed negative values, and thermal strains showed a similar curve to observed ones mostly. Average thermal expansion coefficients in the temperature range from 180 to 300K estimated by mechanical model agreed with the observed ones. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2918–2925, 2004