孕镶金刚石钻头国内外应用

随着世界油气及矿产资源需求的不断上升,人们越来越关注难开发动用储层,希望钻出更多的资源。伴随着开采范围的不断缩小,目前坚硬地层也是人们开发的重点。如何迅速高效的快速钻进,是每个研制部门迫切需要解决的问题。本文详细介绍了适合钻探坚硬地层的孕镶金刚石钻头,并列举了国内外成功实例,希望可以给有此需求的工作人员提供有价值的科技情报。     

浅析中频热压烧结过程中影响金刚石钻头性能的因素

通过试验和分析,说明在中频热压烧结金刚石钻头过程中,钻头性能受各种因素综合影响,其主要因素是电磁场影响到胎体粉料和金刚石分布,模具配合间隙引起胎体的流失而导致金刚石浓度发生变化.文中分析了电磁场对钻头性能的影响与胎体中铁磁物质含量及金刚石浓度的关系,也分析了模具配合间隙对胎体流失而引起金刚石浓度变化的关系.在中频热压烧结,高铁磁质含量胎体和低金刚石浓度的前题下,采用新工艺制作钻头,金刚石分布得到改善,钻头在使用中取得了良好的效果.     

热压烧结BN-AlN复相陶瓷致密化研究

研究了热压烧结BN-AlN复相陶瓷的致密化行为，研究了添加剂的加入量、AlN第二相的含量以及热压温度、保温时间等工艺参数对复相陶瓷致密化的影响。结果表明：当Y2O3的添加量为10％，AlN加入量为50％时，在1900℃，保温2h，压力为30MPa，N2气氛下可以制备出致密的BN—AlN复相陶瓷，对BN—AlN的相组成及显微结构进行了观察分析。     

热等静压强化金刚石钻头性能研究

为提高热压孕镶金刚石钻头力学性能和耐磨性,使之更好地适用于强力规程钻探现场,提出常规热压+热等静压相结合的金刚石钻头制造方法。以2个优选的预合金体系钻头胎体配方为基础,分别采用常规热压、常规热压+热等静压的方式试制钻头胎体和孕镶金刚石钻头进行室内测试和现场试验对比分析。室内测试表明,相较于常规热压烧结方式,采用常规热压+热等静压烧结后,钻头胎体的硬度平均提高2.0 HRC,磨损量平均下降2.3 mg,相对密度达到98.7%和99.1%。现场试验结果表明,引入热等静压烧结之后,相同配方热压金刚石钻头其机械钻速相差不大,但耐磨性明显提高,使用寿命平均提高50.42%。     

热压金刚石地质钻头用石墨模具

近四十年来,我国热压金刚石地质钻头用石墨模具有了长足的进步,但是,与欧美日等发达国家的水平相比,尚有较大的差距。文章通过对国内外石墨模具样品的试验分析,并对碳素材料的氧化机理及其影响因素进行深入地研究,提出要提高热压金刚石地质钻头用石墨模具的尺寸精度、表面光洁度,减少胎体或镶块中金属结合剂的流失量,减缓石墨模具的氧化烧损速度,宜采用超细碳素原料颗粒来制作高电阻率、高石墨化程度、高强度、低灰分、微气孔率的石墨模具。这是赶超世界先进水平的发展方向,也是制取高精度,高使用寿命的热压金刚石地质钻头用石墨模具的有效途径。     

新型金刚石钻头的发展

介绍国内目前最先进的几种新型地质、石油金刚石钻头.对新型金刚石钻头的设计理念、制造工艺及特征进行简述,为金刚石钻头设计制造提供参考.     

块状菱镁矿原矿热压烧结性能

采用热压烧结法,模拟块状菱镁矿在自重压力作用下的烧结过程,研究了热压条件下块状菱镁矿的致密化规律。结果表明:在匀速升温阶段,颗粒迅速致密化,自重压力增加,加快了方镁石颗粒重排速率,缩短了致密化时间,降低了试样致密化温度;在保温阶段,试样以塑性流动和扩散方式致密化;在塑性流动阶段,随着P/η的增大,致密化速率提高,塑性流动过程缩短;扩散阶段,随着保温时间的延长,试样的孔隙度逐渐减小,晶粒逐渐长大;在匀速降温阶段,自重压力越大,试样弹性模量越高,应力释放产生的弹性形变越大,相对密度降低速率越快,自重压力为5MPa时试样的致密化程度和方镁石结晶度最高。     

钻进坚硬致密岩层的金刚石钻头试验研究

文章对坚硬致密岩石的特点进行分析,研究了钻进这类岩石难的原因;在此基础上从金刚石钻头的结构、钻头性能及胎体材料、金刚石参数等方面进行了全面而深入的研究分析,提出压力-磨损因子概念,提出钻头主辅工作层复合结构设计,并研制了两个复合型试验钻头,在野外钻探生产中进行了实钻与测试,并与试验机台使用的其他厂家的普通金刚石钻头进行...     

铁铜类预合金粉末应用于热压金刚石钻头的试验研究

介绍铁铜类预合金粉末应用于金刚石钻头胎体中的试验研究,通过一些基础试验验证其可行性,并经过试制钻头进行钻进试验,证明加入FeCuNi、FeCuCo类预合金粉末的钻头综合性能得到很大提高,为预合金粉末应用于钻头胎体提供了借鉴。     

热压烧结制备高密度ZrB2陶瓷

在烧结温度和压力为1950℃和50MPa条件下,分别对ZrB2的原始粉末、球磨粉末、加助烧剂的粉末以及既加助烧剂又进行球磨的粉末进行热压烧结实验。采用阿基米德排水法测出了ZrB2陶瓷的密度;利用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、能谱(EDS)等手段对粉体和烧结产物的物相、形貌以及成分进行了表征。结果表明:球磨且加助烧剂镍的粉体烧结所得样品致密性最好,相对密度为99.375%,接近全致密;球磨细粉烧结所得样品次之,相对密度为99.09%;添加助烧剂粉末烧结所得样品相对密度为91.45%;用原始粉末烧结所得样品致密性最差,相对密度为84.7%。采用排水法所测得密度结果与扫描电镜观察所得致密性情况一致。     

High-toughness mullite ceramics fabricated by hot-press sintering of pyrophyllite and AlOOH at low temperatures

High-toughness mullite ceramics were fabricated through hot-press sintering (HPS) of pyrophyllite and AlOOH, which were wet-milled and well mixed using a planetary ball mill. The impacts of sintering temperatures and contents of AlOOH on mullite phase formation, densification, microstructure and mechanical properties in ceramic materials were investigated through XRD, SEM and mechanical properties determination. The results indicated that high-toughness mullite ceramics could be successfully prepared by HPS at temperatures higher than 1200°C for 120 min. Increasing the sintering temperature from 1000 to 1300°C significantly enhanced the flexural strength and fracture toughness of samples. The highest flexural strength of 297.97±25.32 MPa and fracture toughness of 4.64±0.11 MPa⋅m^1/2 were obtained for samples sintered at 1300°C. Further increase of temperature to 1400°C resulted in slight decrease of flexural strength and fracture toughness. Compared with the mullite ceramics prepared only using pyrophyllite as raw material, incorporation of AlOOH into raw material significantly increased the mechanical properties of final mullite ceramics. And stoichiometric AlOOH and pyrophyllite as starting material gave the best performance in fracture toughness. The high-toughness of mullite ceramics were ascribed to the high mullite phase content, fine mullite whiskers and in situ formed, intertwined three-dimensional network structure obtained through HPS at a low temperature of 1300°C.     

Fabrication and characteristics of Ce-doped Y3Fe5O12 ceramics by hot-press sintering with oxygen/nitrogen atmosphere

Infrared transparent Ce-doped Y₃Fe₅O₁₂ (Ce_: YIG, Ce_xY_3-xFe₅O_12, x = 0, 0.12, 0.24, 0.36) ceramics were successfully produced by the solid-state reaction using a hot-press sintering process from the Y₂O₃, Fe₂O₃, and CeO₂ powders. The phase structure, microstructure, infrared transmittance, and magnetic and magneto-optical properties of the Ce-doped Y₃Fe₅O₁₂ ceramics were measured and analyzed. The in-line transmittances of the Ce-doped Y₃Fe₅O₁₂ ceramics with the x = 0, 0.12, 0.24 (L = 0.5 mm) at 1550 nm were about 72%, 66.5%, and 57.6%, respectively. In the state of saturation magnetization, the Faraday rotation angle per centimeter (θ_F) of Ce_xY_3-xFe₅O₁₂ (x = 0, 0.12, 0.24) ceramics measured by the light extinction method was 182.5, −410.4, and −958.3 deg./cm, respectively. The change of the θ_F was about −142.5 deg./cm when per 1at.% Ce was substituted in the dodecahedral site of YIG materials. The (Ce_0.24Y_2.76)Fe₅O₁₂ ceramics were determined as the optimized composition for its excellent infrared optical and magneto-optical properties.     

Highly dense 0.3CaCeNbWO8-0.7LaMnO3 composite ceramics fabricated by cold sintering process

The cold sintering process (CSP) has been used for fabricating functional ceramics at a low sintering temperature. In this study, highly dense 0.3CaCeNbWO₈-0.7LaMnO₃ composite ceramics have been successfully fabricated by CSP. The phase structure, microstructure, and electrical properties of composite ceramics have been investigated. The composite ceramic is mainly composed of a tetragonal CaCeNbWO₈ phase with scheelite structure and an orthorhombic LaMnO₃ phase with perovskite structure. The relative density of composite ceramic is 94.5%, and is higher than that of single phase ceramic. The resistivity of composite ceramic exhibits negative temperature coefficient characteristics, with an aging coefficient less than 2%. Such a sintering methodology is of great significance, since it provides a feasible idea for preparing composite ceramics.     

Ultrafast synthesis and densification of ZrO2 doped KNN ceramics by reactive flash sintering

Fabrication of dense KNN-based lead-free piezoelectric ceramics at low temperatures in short time through a cost-effective way remains a challenge. Herein, this challenge could be addressed by using reactive flash sintering. It is demonstrated that the phase transformation of KNbO₃-NaNbO₃ into (K,Na)NbO₃ and densification occur simultaneously during the flash event. Most importantly, ZrO₂ doping can greatly decrease the onset flash temperature, which is ascribed to the increased conductivity of sample. In addition, the current limit has a significant effect on the phase transformation and densification. The flash-sintered KNN ceramics exhibit the good ferroelectric and piezoelectric properties. Furthermore, the ZrO₂ doped and undoped KNN ceramics show a comparable coercive field E_c, which may be related to the residual point defects after the flash. Besides the Joule heating, the avalanche generation of point defects is suggested to be responsible for the ultrafast solid-state reaction and densification rates.     

氮化铝陶瓷低温烧结助剂体系的研究

选用6种配方进行研究，通过XRD、SEM和TGA研究了各配方在升温过程中的物相组成及变化，详细记录了实验中各试样的形貌变化，讨论了相关物质对液相生成温度的影响。研究发现，氟化钙-氧化钇-碳酸锂为最佳体系，氟化钙类似化合物可促进碳酸盐的分解，生成的氧化锂(特定的碱性氧化物)可降低液相生成温度(最低共熔温度)，从而降低液相生成温度，促进烧结进程。     

Powder chemistry effects on the sintering of MgO‐doped specialty Al2O3

In this work, we investigate the effects of powder chemistry on the sintering of MgO‐doped specialty alumina. The stages at which MgO influences densification of Al₂O₃ were identified by comparing dilatometry measurements and the sintering kinetics of MgO‐free and MgO‐doped specialty alumina powders. MgO is observed to reduce the grain boundary thickness during densification using TEM. We show that MgO increases the solubility of SiO₂ in alumina grains near the boundaries using EDS. First‐principles DFT calculations demonstrate that the co‐dissolution of MgO and SiO₂ in alumina is thermodynamically favored over the dissolution of MgO or SiO₂ individually in alumina. This study experimentally demonstrates for the first time that removal of SiO₂ from the grain boundaries is a key process by which MgO enhances the sintering of alumina.     

Demonstration of the cold sintering process study for the densification and grain growth of ZnO ceramics

With the cold sintering process (CSP), it was found that adding acetic acid to an aqueous solution dramatically changed both the densities and the grain microstructures of the ZnO ceramics. Bulk densities >90% theoretical were realized below 100°C, and the average conductivity of CSP samples at around 300°C was similar to samples conventionally sintered at 1400°C. Frequently, ZnO is also used as a model ceramic system for fundamental studies for sintering. By the same procedure as the grain growth of the conventional sintering, the kinetic grain growth exponent of the CSP samples was determined as N=3, and the calculated activated energy of grain growth was 43 kJ/mol, which is much lower than that reported using conventional sintering. The evidence for grain growth under the CSP is important as it indicates that there is a genuine sintering process being activated at these low temperatures and it is beyond a pressurized densification process.     

Impact of reactive precursors on the sintering of tin monoxide

The thermodynamic stability limits of Sn(II) under ambient conditions imposes constraints on the densification of divalent tin based oxides. In the case of tin monoxide (SnO), a low temperature (≤ 300 °C) electric field assisted processing route (Cool-SPS) affords densification up to 90 % of theoretical density. This is demonstrated for both conventional SnO and reactive tin(II) oxyhydroxide [Sn₆O₄(OH)₄] precursor powders. The choice of starting precursor impacts both the optimized processing parameters and the resulting ceramic microstructure. Characterizations of phase content and stability have been performed on both the precursor powders and resulting ceramics. Preliminary electrochemical property measurements are presented and their connection to observed microstructures and choice of initial precursor is discussed.     

Study on robust additive of CaCO3 for fast fabrication of highly transparent AlON ceramics by pressureless sintering

Fabrication of transparent AlON ceramics is extra sensitive to both particle size of starting powder and sintering additive due to shuttling transformation between AlON and Al₂O₃ + AlN during heating. One possible solution is to select robust additive to suppress the shuttling transformation. In this work, three AlON powders with different median particle sizes of 0.6, 0.9, and 1.1 μm were prepared. After studying the effect of CaCO₃ on densification process, AlON ceramics with the maximum transmittance of ≥81.1% were successfully fast prepared by pressureless sintering (PS) at 1880°C for only 2.5 h by using three AlON powders doped with different CaCO₃ amount. Specifically, AlON ceramics prepared from 1.1 μm with 0.5–0.8 wt.% CaCO₃ doping consistently showed the maximum transmittance of ≥85.3%, which indicates that CaCO₃ can serve as a robust additive to enable fast fabrication of highly transparent AlON ceramics even by PS.     

微波强化烧结制备铁钴基金刚石锯片刀头

采用微波烧结技术制备了低钴型Fe-Co基金刚石锯片刀头,利用圆柱谐振腔微扰法电磁特性测试系统评价了配方物料压坯的吸波特性,并结合物料在微波场中的升温特性设计了可行的微波烧结制度。采用SEM、致密度和硬度测试对比研究了微波烧结和常规烧结所得样品的微结构信息和力学性能。结果表明,对于低钴高铁型配方,在850℃下微波烧结获得的样品,其相对致密度和硬度即可分别达到96.63%和99.4HRB,微波烧结在最大升温速率为32.5℃/min时能保证烧结体组织均匀。与常规烧结方法相比,在获得同等级力学性能的前提下,微波强化烧结可将温度降低至900℃以下,显著缩短了烧结总时间,在金属基金刚石工具刀头烧结方面表现出良好的应用前景。