Fe和WC两种骨架相对金刚石地质钻头性能的影响研究

通过对比Fe和WC两种材料作为骨架相时胎体烧结体的力学性能差异,来研究骨架材料对金刚石地质钻头胎体配方性能的影响。在不同的骨架相配方体系下通过测试胎体的三点抗弯强度τ0、强度损失率σ、硬度HRB及磨损失重Δm来研究它们之间的力学和磨损性能的差异。再通过实际钻进实验去验证钻进效果。研究结果表明:以WC为骨架相时钻头有更好的力学性能及钻进寿命,以Fe基为骨架相的钻头具有更高的钻进效率,但寿命较低。     

稀土元素La对金刚石钻头胎体的性能影响

文章研究了微量La元素的添加对金刚石钻头胎体的抗弯强度、磨损失重、硬度等力学性能的影响。并通过扫描电镜对不同样品断口形貌进行了分析对比。研究结果表明：加入微量的La元素,胎体的抗弯强度τ0有所上升,磨损失重Δm有所下降,硬度HRB基本没有太大变化。含金刚石试样的断口形貌电镜照片表明：微量La元素的加入,可以减少胎体中的孔洞缺陷,改善胎体的组织结构,提高胎体的力学性能。     

铁对铜基结合剂金刚石节块把持力的影响

采用热压烧结的方法得到了不同铁含量的铜基结合剂金刚石节块,研究了铁含量对铜基结合剂金刚石节块性能的影响.实验结果表明:铁含量对铜基结合剂胎体的硬度和抗弯强度等力学性能有显著的影响;随着铁含量的增加,铜基结合剂胎体的硬度和抗弯强度一直增加;铁含量对铜基结合剂金刚石节块的抗弯强度的影响不一样.界面处断口形貌和能谱分析表明:当铁含量为30％时,铜基结合剂与金刚石结合最好,胎体对金刚石的把持力系数较大,节块的抗弯强度降低较少.     

Cu和Ni的化合物对金刚石钻头胎体性能的影响

主要研究了在铁基胎体配方F15#的基础上添加不同量的含Cu或Ni的化合物对金刚石钻头胎体性能的影响。根据不同配方制作标准试样块,测试其硬度HRB、抗弯强度和磨耗比,以此来评价胎体的力学性能和耐磨性能,同时优选出配方制作钻头进行实际钻进试验。试验结果表明:随着胎体中Cu或Ni的化合物含量的增加,胎体的硬度、抗弯强度都呈现下降的趋势,胎体样块的磨耗比也逐渐下降,表明了钻进效率的提高,从实际钻进结果可知,钻头的钻进效率得到了提高,寿命也比较好。     

预合金粉替代单质粉制备金刚石工具胎体的研究

分别以Cu_(85)Sn_(15)、Y1(Fe_(60)Co_(25)Cu_(15))、Y2(Fe_(66)Co_(27)Cu_7)、Fe_(70)Cu_(30)预合金粉替换胎体配方中的Co、Fe、Cu、Sn单质粉,设计了配方组合SY1～SY5。通过对比分析各配方烧结试样的致密度、断口显微形貌、硬度、抗弯强度和韧性,研究加入预合金粉后胎体性能的变化。实验结果表明,采用预合金粉Y1/Y2替换配方中的Co粉,试样致密度和硬度有所下降,抗弯强度和韧性显著提升;加入Y1的试样硬度要高于加入Y2的,加入Fe_(70)Cu_(30)合金粉的试样硬度高于加入Fe和Cu单质粉的。     

不同Zn-Sn含量的铁基结合剂的耐磨性研究

本文在铁基结合剂中加入Zn和Sn含量分别为0%、2.5%、5%、7.5%、10%和10%、7.5%、5%、2.5%、0%;采用热压烧结制备出不同Zn和Sn含量的铁基结合剂样品,并对铁基结合剂样品的密度、硬度和耐磨性进行了测试。实验数据表明:铁基结合剂中加入Sn含量在2.5%左右,Zn含量在7.5%左右时,铁基结合剂的硬度最高,耐磨性最好。     

超细铁铜锡磷预合金粉在高铁基金刚石工具中的性能研究

通过粉末冶金工艺制备了铁含量在70%～80%之间的金刚石工具胎体试样,研究了化学法生产的超细Fe-Cu-Sn-P预合金粉(添加比例在20%～60%)对高铁基胎体物理性能、机械性能和切割性能的影响。在密度天平、洛氏硬度计、拉伸试验机、扫描电子显微镜上分别测试试样的密度、硬度、抗压强度以及三点弯曲强度、断口形貌。结果表明:添加超细预合金粉有助于提高胎体的压制成型性,在实际生产中,建议添加比例控制在30%～50%;随着超细预合金粉含量的增加,试样的硬度和抗弯强度随之提高,合金粉含量达到50%以后试样的硬度和抗弯强度提高幅度变缓;随着超细预合金粉末含量的增加,胎体的烧结温度随之降低,其中A5的烧结温度比A1的烧结温度降低35℃;超细预合金粉末含量达到40%以后锯片切割五莲红的锋利度得到了明显提升。     

超细铁铜锡磷预合金粉在高铁基金刚石工具中的性能研究

通过粉末冶金工艺制备了铁含量在70%～80%之间的金刚石工具胎体试样,研究了化学法生产的超细Fe-Cu-Sn-P预合金粉(添加比例在20%～60%)对高铁基胎体物理性能、机械性能和切割性能的影响。在密度天平、洛氏硬度计、拉伸试验机、扫描电子显微镜上分别测试试样的密度、硬度、抗压强度以及三点弯曲强度、断口形貌。结果表明:添加超细预合金粉有助于提高胎体的压制成型性,在实际生产中,建议添加比例控制在30%～50%;随着超细预合金粉含量的增加,试样的硬度和抗弯强度随之提高,合金粉含量达到50%以后试样的硬度和抗弯强度提高幅度变缓;随着超细预合金粉末含量的增加,胎体的烧结温度随之降低,其中A5的烧结温度比A1的烧结温度降低35℃;超细预合金粉末含量达到40%以后锯片切割五莲红的锋利度得到了明显提升。     

高强度低成本石油钻头胎体配方的研究

文章以铁(Fe)为主体,以碳化钨(W2C)为辅助骨架,以铜(Cu)和镍(Ni)为粘结剂和浸渍合金,研制开发了三种高性能石油钻头胎体配方。首先依据胎体配方制备预合金粉末,然后测试胎体配方的抗弯强度和抗冲击韧性等性能,最后加入金刚石,试制钻头。实验结果表明,采用三种胎体配方所制备钻头的抗冲击韧性和抗弯强度都远高于行业标准的要求,表明钻头试制成功;新配方的成本比现用的胎体降低1/3左右。该项目研究在钻头制造中取得了突破性进展,提高了钻头在井内复杂环境下的工作能力,并降低了钻头成本。     

烧结温度对金刚石绳锯串珠性能的影响

测试烧结温度对Fe基胎体力学性能中的抗弯强度、硬度和绳锯使用性能的影响。采用相同的Fe基配方进行变温恒压的实验块测试,验证其硬度及抗弯强度变化;同时制作三条长度一致的金刚石矿山绳锯进行切割测试,制备的串珠分别在850℃、875℃、900℃条件下进行烧结,切割测试记录金刚石绳锯每一次的切割效率。实验块测试结果表明,烧结温度越高,实验块的抗弯强度、硬度也随之升高。矿山绳切割测试结果表明,串珠在低温情况下制备的绳锯产品使用效率远好于高温情况。     

BF/黑宝石粉体增强EP基摩擦材料的摩擦磨损性能

以环氧树脂(EP)为基体,玄武岩纤维(BF)为增强材料,玄武岩水晶玻璃(黑宝石)粉体为摩擦性能调节剂制备BF/黑宝石粉体增强EP基摩擦材料,研究了黑宝石粉体对摩擦材料摩擦磨损性能和力学性能的影响,然后在添加质量分数为5%的黑宝石粉体的基础上,采用相同手段研究了BF含量对摩擦材料性能的影响。结果表明,黑宝石粉体可以极大地提高摩擦材料的摩擦系数,并进一步降低磨损率以及提高摩擦材料的力学性能。BF的加入在一定程度上降低了摩擦材料的摩擦系数,且当BF含量较低或较高时,摩擦材料的磨损率均会有所提升。当BF质量分数为6%时,摩擦材料的综合性能最优,其摩擦系数为0.534,与未加BF的摩擦材料相比仅降低了7.61%,磨损率为0.75%,较未加BF的摩擦材料降低了31.82%,拉伸强度和弯曲强度分别为55.568 MPa和92.750 MPa,与未加BF的摩擦材料相比,分别提高了148%和66.42%。     

Effect of interfacial weight loss by silver migration on the pullout strength of a silver wire embedded in an adhesive matrix

In this study an effort is made to correlate interfacial weight loss, by migration, from the surface of a silver wire embedded in an adhesive matrix, to bond strength between the silver wire and the adhesive matrix. Comparative studies are also performed using an aluminum an wire in place of silver to accurately assess the effect of interfacial weight loss by silver migration. The results of the pullout tests on silver migrated specimens are compared with pullout tests on silver-wire specimens, which were immersed in water for 2 h but without silver migration. Pullout tests are performed in both wet, and dry conditions of the bonded specimens. It is determined that the pullout strength of bonded silver-wire specimens in wet condition decreases by as much as 86%, subsequent to silver migration. The loss of bond strength for silver-migrated specimens tested in dry condition varies between 23% and 4%, depending on the embedded length used.     

ZTA材料性能的研究

以α—Al2O3和钇稳定氧化锆为主要原料,采用应力诱导相变增韧和微裂纹增韧的机理,以钇稳定氧化锆质量分数分别为15%,20%,25%,30%不同比例进行试验,来制备ZTA陶瓷材料。测定其密度、弯曲强度和磨耗等物理性能,研究了不同钇稳定氧化锆含量对ZTA陶瓷材料性能的影响,分析了影响产品性能的因素,得出了钇稳定氧化锆含量越高材料性能越好的结论。     

高温处理对酚醛树脂基复合材料性能的影响

以自制的酚醛树脂(PF)为基体,玻璃纤维布(GFC)、高硅氧玻璃纤维布(HSGFC)和碳纤维布(CFC)为增强体,采用铺层模压法制备了PF/GFC,PF/CFC和PF/HSGFC复合材料,并在200~800℃范围内对复合材料进行了高温处理,研究了不同处理温度对这3种复合材料失重率和力学及烧蚀性能影响。结果表明,当处理温度高于400℃后,3种复合材料的失重率随处理温度升高逐渐增大,其中,PF/CFC的失重率最大,而PF/GFC的失重率最低;但800℃下3种复合材料的失重率均在10%以下。随处理温度升高,3种复合材料的弯曲强度、压缩强度、拉伸强度总体上均先增大后减小,当处理温度为400℃达到最大,烧蚀性能具有与力学性能相反的变化趋势。在400℃的处理温度下,PF/GFC的弯曲强度、质量烧蚀率和线烧蚀率最高,拉伸强度最低;PF/CFC的压缩强度、拉伸强度最高,线烧蚀率最低;而PF/HSGFC的压缩强度和弯曲强度最低,其质量烧蚀率也最低。     

紫外老化对UP/GF层合板性能的影响

对玻璃纤维增强不饱和聚酯树脂(UP/GF)基层合板进行了人工紫外加速老化试验,分析了试样紫外老化前后的巴氏硬度、质量保持率以及拉伸、弯曲性能的演变规律。结果表明,随紫外老化时间的增加,试样的巴氏硬度呈先上升后下降的趋势;紫外老化最初的168 h内,质量损失率占整体质量损失的近50%,之后保持在一个相对平稳的状态;其拉伸强度和弯曲强度在紫外老化前期有所上升,在紫外老化168 h开始下降;从傅立叶变换红外光谱图中可以看出,试样中没有新的物质产生,只是化学结构发生了变化;紫外老化后,UP含量明显减少,在拉伸断裂过程中,有明显的玻璃纤维从UP树脂中拔出而留下凹槽空洞。     

Effect of polyethylene glycol on mechanical properties of bamboo fiber-reinforced polylactic acid composites

The bamboo fiber (BF)-reinforced polylactic acid (PLA) composites were prepared using the twin-screw extruder and injection molding. Thermal gravimetric analyzer results indicated the thermal stability of BF/PLA composites decreased with increasing BF content. Differential scanning calorimeter and X-ray diffraction curves showed that BF played a role as a nucleating agent, but the crystallinity of composite materials decreased with the increasing BF content. The melt flow rate of composites reduced with the increase in BF content, resulting in a poorer processing property. The processability of the composites was improved with the addition of high molecular polyethylene glycol (PEG). Mechanics performance test showed that tensile strength and bending strength of composites increased at low loading with the BF content increased then decreased when the loading continued to increase. The tensile strength of the composite materials reached 65.46 MPa when alkali-treated BF (ABF) content was 20 wt %. The flexural strength of the composites reached 97.94 MPa when ABF content was 10 wt %. Impact performance has also been improved. PEG-20000 was the best plasticizer among the PEG-6000,PEG-10000, and PEG-20000. When the component of PEG was 10 wt %, the elongation increased by 56%. The scanning electron microscopy (SEM) result showed that the fracture of the composites was smooth, most ABF were wrapped in matrix and distribution of ABF in PLA matrix was more uniform. It means that interfacial compatibility of bamboo fiber and PLA improved after BF modified by alkali. High molecular weight PEG enhance melt flow ability of polymer, result in fibers were further enclosed in the PLA matrix and increase properties of composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47709.     

Oxidation behaviors and shear properties of z-pinned joint made of two-dimensional carbon fiber reinforced silicon carbide composite

Chemical vapor infiltration has been introduced for preparing z-pinned joint, which is made of two-dimensional carbon fiber reinforced silicon carbide composite. The effects of oxidation on the shear properties of the joint were investigated. The results showed that the joint strength increases with the increase of oxidation temperature, which is consistent with the oxidation consumption of the carbon phases. An exponential relationship is presented between the weight loss and the joint strength. In contrast, linear relationships are presented between the weight loss and the mechanical properties of the composite. The exponential relationship results from the coupled shear and bending stress states of the pin, according to the failure mechanisms of the joint. It is observed that in-plane and intra-layer cracks are formed under the shear stress. And these cracks are bridged by the fibers under the bending stress. Accordingly, the fiber bridging mechanism contributes to the joint strength before and after oxidation. For the conditions of this study, the joint strength can be roughly estimated as the plus of the in-plane shear strength and the tensile matrix cracking stress.     

尼龙6/纳米A12O3复合材料与铜摩擦副的摩擦磨损性能

采用双螺杆挤出机共混制备尼龙6／纳米Al2O3复合材料,考察了复合材料的硬度及与铜摩擦副的摩擦磨损性能。试验表明,加入纳米Al2O3可使尼龙6的硬度提高。在低载荷时,复合材料的摩擦系数随载荷的增加而减小;当载荷超过一定值后,摩擦系数增大;载荷一定时,摩擦系数随纳米A120,含量的增加呈上升趋势。当纳米Al2O3含量达到10份时,复合材料的磨损量较小;当纳米Al2O3超过10份时,纳米Al2O3粒子的团聚会造成其与基体尼龙6的结合力降低,最终导致尼龙6／纳米Al2O3复合材料磨损量增大。     

硫酸钙晶须对E-44环氧树脂的微结构与力学性能的影响

以E-44环氧树脂为基体,硫酸钙晶须（CSW）为增强材料制备了硫酸钙晶须／环氧树脂复合材料,研究了不同硫酸钙晶须含量对复合材料的拉伸强度、弯曲强度、磨损量及耐热温度的影响。结果表明,复合材料的力学性能、磨损量及耐热性均有所提高,拉伸强度和弯曲强度分别提高了25％、51％,磨损量降低了54％,耐热温度提高了7．9℃。由SEM表明,试样断面光滑,属于脆性断裂。