烧结温度对CuZnSn13粉末烧结体组织和性能的影响

分别选用CuZnSn13雾化预合金粉末和Cu、Zn、Sn单质机械混合粉末为原料,通过热压烧结法制备CuZnSn13合金,采用扫描电子显微镜、X射线衍射仪等手段对烧结组织进行分析,运用排水法、洛氏硬度计和万能试验机测试致密度、硬度和抗弯强度。结果表明:相同烧结条件下,两种烧结体主要组成相基本相同;但是,和单质机械混合粉烧结体相比,预合金粉烧结体中固溶相更多,并存在少量硬脆相Cu₆Sn₅和Cu₆₁Zn₃₉相,组织更加均匀细小;两种烧结体随烧结温度的升高,致密度、硬度和抗弯强度整体呈上升趋势,但预合金粉烧结体的性能随温度变化幅度不明显。      

CSB-2预合金粉质量分数和烧结温度对热压富铁基胎体力学性能的影响

热压富铁基金刚石钻头具有成本低、钻速高的优点,已在钻探中广泛应用。对比相同的热压富铁基胎体配方,通过测试试样的致密度、显微硬度、抗弯强度和抗冲击韧性,研究CSB-2预合金粉质量分数和烧结温度对金刚石钻头胎体力学性能的影响。试验结果表明:添加CSB-2预合金粉的胎体性能均比单质混粉胎体性能好。随CSB-2质量分数的增加,胎体的致密度、显微硬度、抗弯强度和抗冲击韧性分别最大提高了7.68%、27.99%、94.43%和312.82%;同时,胎体粉末预合金化有利于降低胎体的热压烧结温度;为获得良好的应用效果,CSB-2质量分数应大于30%,且最佳烧结温度为940~980℃。      

脱蜡工艺对超细预合金胎体中碳氧含量的影响

为提高超细预合金粉末的流动性、冷压性能,需加入制粒剂对超细预合金粉末进行制粒,再通过还原脱蜡工艺和随炉保温脱蜡工艺2种脱蜡方法去除。结果表明:超细预合金粉末制粒后无论采用还原脱蜡工艺还是随炉保温脱蜡工艺脱蜡,烧结后的胎体都会有制粒剂残留从而使碳含量增加;还原脱蜡工艺处理的胎体中碳、氧质量分数最低,分别为0.048%和0.22%,但随炉保温脱蜡工艺通过延长保温时间,胎体中碳含量也可以达到还原脱蜡工艺的水平。在随炉保温脱蜡工艺下,试样氧含量不随保温时间增加而降低,只与烧结条件有关,高温烧结时石墨模具内产生还原性气氛使试样氧含量降低。2种脱蜡方法对超细FeCoCu预合金粉末胎体的抗弯强度和洛氏硬度影响不大。      

烧结压力对低液相Fe基预合金钻头胎体性能的影响

在烧结温度为950℃、保温时间为5 min及不同烧结压力条件下开展热压烧结试验，对比研究烧结压力对3种低液相Fe基预合金钻头胎体和1种传统Fe基钻头胎体性能的影响，具体包括胎体压入硬度、抗弯强度、致密度和金刚石包镶强度等力学性能，以及金刚石的热损伤情况和钻头胎体的微观组织结构与形貌特征等。结果表明：随着烧结压力增大，低液相空白胎体的压入硬度、抗弯强度和致密度逐渐增大，而传统Fe基空白胎体的压入硬度和抗弯强度呈现先增大后减小的趋势，其致密度为增大趋势；对于含金刚石的胎体，低液相与传统Fe基胎体抗弯强度均随烧结压力增大而增大，当烧结压力为20 MPa时，继续增大压力，低液相含金刚石胎体的抗弯强度趋于稳定，而传统Fe基含金刚石胎体的抗弯强度略有下降。同时，随着烧结压力的增大，低液相胎体的均一性明显增强，但金刚石的热损伤加剧。综合胎体的力学性能与断口形貌特征，优选的烧结压力为20 MPa，此时的低液相Fe基预合金胎体硬度、抗弯强度可满足孕镶金刚石钻头需要。     

第二代FeCuCo预合金粉末的烧结与力学性能研究

采用国产真空热压烧结机制备了第二代FeCuCo预合金粉末的胎体试样,着重研究了不同烧结温度对胎体的断口形貌、相对密度、硬度和抗弯强度的影响。结果表明:在选定的不同热压烧结温度下,胎体的断口均为沿晶断裂和穿晶断裂的混合型断口,胎体的晶粒尺寸比较均匀;随着烧结温度的升高,胎体内的晶粒逐渐长大,但没有发生异常长大现象,胎体的相对密度先略有升高然后恒定不变,硬度一直呈下降趋势,抗弯强度先升高后下降;在30 MPa保压6 min的条件下,第二代FeCuCo预合金粉末的最佳烧结温度为850℃,此时胎体的相对密度为97.5%,硬度为105.5 HRB,抗弯强度为1 839.14MPa。     

粉末预合金化对金刚石工具胎体性能的影响

本文通过试验分析研究了铁基粉末预合金化对金刚石工具胎体硬度与抗弯强度的影响.结果表明:预合金粉末烧结温度较低,胎体在750 ℃即可得到高的烧结硬度,为106 HRB,在650 ℃～900 ℃的烧结温度区间内,硬度值变化仅小于4 HRB;而在相同的烧结温度下,相同组分的混合粉末的烧结硬度仅为94 HRB～98 HRB;当烧结温度低于800 ℃时,预合金粉末胎体抗弯强度低于混合粉末胎体;随着烧结温度的升高,二者差距缩小.预合金粉末胎体的最佳结烧结温度区间为750 ℃～850 ℃,在此范围内可得到讲最佳的硬度与抗弯强度匹配.     

铁基非晶粉末对金刚石工具胎体的影响

将不同质量分数（分别为0,5%,10%和15%）的铁基非晶粉末加入铁基预合金粉末胎体中,通过热压烧结制成胎体试样后,测试其洛氏硬度、抗弯强度及磨损率。当不添加非晶粉末时,普通胎体的洛氏硬度、抗弯强度和磨损率分别为104.6 HRB, 610 MPa和3.3;加入10%的非晶粉末后,其洛氏硬度和抗弯强度分别提高至107.7 HRB和965 MPa,比原胎体分别提高了3.0%和58.2%,磨损率降低至0.9,降低了72.7%;加入15%的非晶粉末后,其洛氏硬度和抗弯强度分别提高至110.0 HRB和790 MPa,分别提高了5.2%和29.5%,磨损率降低至0.6,降低了81.8%。因而铁基非晶粉末的加入可以显著提高胎体试样的机械性能和耐磨性。此外,铁基非晶粉末的DSC及XRD测试发现,在500～700℃时,铁基非晶粉末会产生晶体化相变,NiSi相中融入了B元素转化成NiSiB相,CrFe相中融入了Si元素形成SiCrFe相,都起到改善胎体结构、提高胎体性能的目的。     

一种激光焊接金刚石锯片过渡层用预合金粉末的性能研究

本文介绍了激光焊接金刚石工具的发展以及预合金粉末在激光焊接金刚石工具过渡层中的应用.分别对预合金粉末和混合粉末烧结得到的胎体进行了三点抗弯强度实验和焊接实验.实验结果表明:自行研制的超细预合金粉末S-1的烧结温度在750～850 ℃,抗弯强度在800～1300 MPa,激光焊接强度高于40 N·m,焊接强度变化小于4 N·m;在800 ℃烧结时,与混合粉末比较,使用超细预合金粉末,胎体的三点抗弯强度由1050 MPa提高到1300 MPa,焊接强度由36 N·m提高到44 N·m.     

低压烧结温度对YG15粗晶硬质合金性能的影响

采用低压烧结方法制备YG15粗晶硬质合金,研究了烧结温度对硬质合金组织和性能的影响,采用扫描电子显微镜观察硬质合金显微组织,固体密度测量组件测试合金致密度,采用洛氏硬度计、万能试验机、矫顽磁力计分别测试合金的洛氏硬度、抗弯强度和矫顽磁力。对不同烧结温度下的性能比较分析得出:YG15粗晶硬质合金的孔隙度A02B00C00,硬度86.0~88.1 HRA,抗弯强度3 018~3 426 MPa,矫顽磁力5.45~6.20 k A/m,1 360、1 375℃低压烧结时,合金的密度、硬度和抗弯强度都较高,而1 390、1 400℃低压烧结时性能下降,1 375℃是YG15粗晶硬质合金的最佳烧结温度。     

超高压水雾化制备预合金粉末在金刚石工具中的应用（英文）

采用超高压水雾化工艺制备金刚石工具用铜基、铁基、钴基预合金粉末,并对超高压水雾化法、常规水雾化法以及单质金属机械混合粉末制备的金刚石工具烧结节块的力学性能、胎体对金刚石的把持力、空白与含金刚石胎体烧结节块的断口形貌进行测定、比较与分析。结果表明:超高压水雾化预合金粉末烧结节块的相对密度、硬度和抗弯强度等力学性能有显著提高。超高压水雾化预合金粉末烧结节块断口形貌为韧性断裂,预合金粉末与金刚石之间除具有机械嵌镶力外,还存在化学结合力,胎体粉末材料对金刚石的把持能力明显增强。采用超高压水雾化预合金粉末可大大改善金刚石制品胎体的力学性能与使用寿命。     

Effect of nano-vanadium nitride on microstructure and properties of sintered Fe-Cu-based diamond composites

With FeCu₃₀ pre-alloy powder as the main component of the bond, a new type of nano‑vanadium nitride (VN) additive with different concentrations was introduced into Fe-Cu-based diamond composites to investigate the effect of nano-VN on the microstructure and properties of Fe-Cu-based diamond composites. The hardness, relative density, bending strength and wear loss weight of the fabricated specimens were tested, and then the fracture surfaces and worn surfaces of those specimens were analyzed using scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The results show that the Fe-Cu-based diamond composites with nano-VN addition exhibited an improvement in the mechanical properties, plasticity and wear resistance, which can be attributed to the dispersion strengthening and grain refinement caused by nano-VN. And the nano-VN can also activate sintering, which can significantly improve the wettability of the binder to diamonds, resulting in more binder elements wetting and diffusion on the diamond surface during the sintering process. Besides, the diamond composites showed the best properties with the addition of 2% nano-VN. That is, the bending strength and the HRB hardness of the diamond composites increased by 25% and 20%, respectively, and the wear resistance of the matrix and holding force coefficient of the matrix to diamond were improved significantly. But an excessive amount of nano-VN was detrimental to the mechanical properties of Fe-Cu-based diamond composites.     

预合金粉结合剂真空无压烧结制备金刚石工具

以Fe₄₀Cu₄₀Co₂₀和Cu₈₀Sn₂₀预合金粉为结合剂,采用真空无压烧结制备金属胎体样品,并与相同烧结工艺下的金属单质粉结合剂烧结样品进行对比。用扫描电子显微镜、洛氏硬度计、阿基米德排水法对所得样品的微观形貌、硬度和相对致密度进行对比分析。研究发现:随温度升高,两类样品的致密度和硬度均先增大后减小;当烧结温度达到860℃时,致密度和硬度均达到最大值。预合金粉在860℃下烧结所得样品的相对致密度比同条件下烧结的金属单质粉样品的提高5%,硬度提高HRB 7 MPa。因此,在达到同等级性能的前提下,预合金粉真空烧结所得样品的烧结温度更低,可有效避免在高温条件下金刚石的强度和质量损失。      

Influence of B4C coating on graphitization for diamond/WC-Fe-Ni composite

Diamond/WC-Fe-Ni composite is a potential composition for impregnated diamond drill bits. It is necessary to avoid the graphitization of the diamond from Fe and Ni under the powder metallurgy process. Boron carbide (B₄C) was coated on diamond, and diamond/WC-Fe-Ni composites were consolidated by hot pressing at different temperatures. The influences of sintering temperature and interfacial structure on bending strength and wear behavior were investigated. The bending strength for diamond/WC-Fe-Ni composite was dependent on matrix densification and interfacial graphitization. Un-coated diamond was eroded by Fe-Ni matrix and partially converted to graphite during the sintering process at all sintering temperatures. In opposite, B₄C coating was beneficial to matrix densification at a lower sintering temperature, and delayed the appearance of graphitization to around 1300 °C. Therefore, the diamond/WC-Fe-Ni composites with B₄C coating exhibited larger bending strength and better wear behavior at a relative low sintering temperature.     

预合金粉对金刚石复合体组织结构影响及机理分析

文中以热压烧结金刚石刀头胎体材料为研究对象,对比分析了添加不同比例的FCu14预合金粉对金刚石刀头孔隙率、硬度、抗剪强度、抗弯强度等性能的影响.结果表明,随着FCu14预合金粉含量的增加,胎体合金成分均匀化,微细的铁基胎体被铜基粘结相均匀地包围,减少了孔隙的存在.胎体的孔隙率明显降低,孔隙均匀细小,因而金刚石刀头胎体硬...     

预合金粉含量对铁基胎体微观组织及性能的影响

研究添加2%、6%、10%和14%质量分数的CuZnSn预合金粉,对金刚石陶瓷磨边轮铁基胎体热压烧结组织、物相组成及力学性能的影响。结果表明:不添加预合金粉烧结的铁基胎体主要包括灰白色、浅灰色和深灰色3种组织,存在的物相主要为γ-Fe、(Cu, Sn)和(γ-Fe, Ni)固溶体以及Fe₄Cu₃、Cu₄₁Sn₁₁、Ni₄Sn等金属间化合物;加入预合金粉后,烧结工艺相同时,胎体中灰白色组织面积明显减少,浅灰色组织面积增加,深灰色组织面积变化不明显,除上述物相外,还出现了Cu_0.61Zn_0.39和CuZn₂物相。随着CuZnSn预合金粉含量增加,铁基胎体的致密度、硬度、抗弯强度均呈先增大后减小的趋势,而磨损量则呈先减少后增加的趋势;在CuZnSn添加质量分数为6%时,分别达到最大值99.8%、104.4 HRB、947.2 MPa和最小值0.272 5 g。添加适量CuZnSn预合金粉可以增加铁基胎体的液相量,改善粉体流动性,提高胎体性能,添加过量则会降低其综合性能。      

Effect of Fe-based pre-alloyed powder on the microstructure and holding strength of impregnated diamond bit matrix

An iron-rich pre-alloyed powder was selected out, and the pre-alloying degree of matrix materials and the sintering temperature were considered to investigate the effect of the Fe-based pre-alloyed powder on the microstructure and holding strength of impregnated diamond bit matrix. And relative density and bending strength of the specimens were measured, and then the resulting fracture surfaces were analyzed using scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The results showed that the relative density, bending strength and plasticity of matrix materials are increased with the sintering temperature and the pre-alloying degree. The influence of the pre-alloying degree on them is more significant than that of the sintering temperature within the experimental parameters. Besides, Fe-based matrices have thermal corrosion effect on diamonds at high temperature sintering process. And the rate of diamond graphitization has a greatly increase with the sintering temperature changes from 900 °C to 1020 °C and the holding strength decreases. A low pre-alloying degree accelerates the rate of diamond graphitization. But an adequate pre-alloying degree of Fe-based matrix materials is conducive to improve the wettability of the matrix to diamonds, alleviate the diamond graphitization, reduce the diamonds' thermal damage and improve the holding strength. Besides, it can also greatly reduce the sintering temperature and broaden the sintering temperature range. In a word, it is feasible and reasonable that Fe-based pre-alloyed powders replace Fe elemental powders to fabricate impregnated diamond bits. And it has a good economic value and broad application prospect.     

磷铁含量对高铁基胎体性能的影响

本文采用粉末冶金方法制备了高铁基胎体的金刚石工具。通过检测材料的硬度、密度、冲击韧性等性能考察了磷铁的加入量对高铁基胎体性能的影响。通过X衍射图、金相图等揭示了磷铁加入量对胎体微观结构变化的影响。结果表明:随着P-Fe含量的增加,胎体的相对密度增加,胎体硬度几乎呈直线上升,含3%磷铁的胎体硬度为HRB97,而含15%磷铁的胎体硬度达到了HRB113。而胎体的抗弯强度、冲击韧性随加入量的增大而减小。脆性的增加对提高胎体的切割性能有益。SEM观察结果表明:随P-Fe的加入量增大,胎体的断裂是脆性断裂为主的韧-脆断裂向脆性断裂过渡。     

超细钨铜合金粉末在金刚石工具中的应用研究

采用超细钨铜合金粉末和单质钨、铜粉末热压烧结成两组金刚石胎体块,利用硬度计,排水法,万能实验机,扫描电镜和锯切实验等测试分析手段分别分析测量了胎体的硬度、致密度、抗弯强度、断口形貌和锯切性能。实验结果表明:在高钨基胎体配方中添加超细钨铜合金粉末比添加单质钨、铜粉末可以显著提高胎体的硬度10 HRB左右,改善胎体合金使之均匀化,在本实验配方中,干切硬花岗岩时,高钨基胎体配方中添加超细钨铜合金粉末比添加单质钨、铜粉末切割平稳,形成胎体和金刚石有效的磨损匹配,可以显著提高工具的使用寿命30%左右。烧结温度范围内,添加合金粉的胎体抗弯强度均比添加单质钨、铜粉末低100 MPa左右,这主要是使用的超细钨铜粉末的氧含量较高所致。     

烧结温度对Ti_3AlC_2/ZA27复合材料性能的影响

以Ti_3AlC_2粉和锌铝合金ZA27粉作为原料,采用行星球磨混料和气氛保护烧结工艺制备了Ti_3AlC_2颗粒增强ZA27复合材料,重点研究了烧结温度对复合材料的相组成、力学性能和显微组织的影响。结果表明,随烧结温度的升高,复合材料的相对密度、维氏硬度、抗弯强度和抗拉强度都增大,且在870℃时抗弯强度和抗拉强度都达到最大值,分别为592和324 MPa。该温度下Ti_3AlC_2与ZA27之间发生了微弱的化学反应,有利于改善基体与颗粒增强相之间的界面结合效果。