【摘要】：聚晶金剛石復(fù)合片（polycrystalline diamond compact，PDC）是聚晶金剛石薄層通過(guò)金屬或者非金屬粘結(jié)劑粘結(jié)在硬質(zhì)合金基體上形成的復(fù)合材料，通常通過(guò)將硬質(zhì)合金襯底和金剛石微粉組裝成模具在高溫高壓條件下燒結(jié)而成。合成的復(fù)合片既有金剛石聚晶的高的耐磨性、高的硬度和導(dǎo)熱性，同時(shí)還兼有硬質(zhì)合金的高韌性、可焊接性和強(qiáng)度。其應(yīng)用領(lǐng)域廣泛，主要用于石油鉆井、煤炭開采、地質(zhì)鉆探、制造切削刀具等。 本文對(duì)傳統(tǒng)的聚晶金剛石復(fù)合片的組裝模具結(jié)構(gòu)進(jìn)行了改進(jìn)：（1）在葉臘石內(nèi)部采用白云石代替葉臘石；（2）改用鹽管代替立方氮化硼作為高壓反應(yīng)的傳壓介質(zhì)；（3）采用三層金屬杯代替?zhèn)鹘y(tǒng)的金屬箔結(jié)構(gòu)。 采用鉸鏈?zhǔn)絿?guó)產(chǎn)六面頂壓機(jī)63600T，利用Co和Si粉熔融滲透催化的方法成功合成了生長(zhǎng)型Φ19mm鉆探用高耐熱性聚晶金剛石復(fù)合片。確定的合成工藝為：合成壓力5.5-7GPa，合成溫度1650℃-1750℃，，合成時(shí)間為10min。 采用XRD、EDX、SEM、DSC-TG等分析手段，對(duì)合成的高熱穩(wěn)定性金剛石復(fù)合片進(jìn)行了微觀組織結(jié)構(gòu)、殘余應(yīng)力檢測(cè)，并在性能表征與優(yōu)化等方面進(jìn)行研究。同時(shí)對(duì)合成PDC的耐熱性、拉曼光譜、殘余應(yīng)力、硬度等性能進(jìn)行了測(cè)試。 對(duì)高熱穩(wěn)定性復(fù)合片進(jìn)行了TGA-DTA分析，結(jié)果表明：常規(guī)金剛石復(fù)合片的初始氧化溫度為780℃，本文研制的高熱穩(wěn)定性復(fù)合片的初始氧化溫度為820℃，耐熱性提高40℃。 對(duì)高熱穩(wěn)定性金剛石復(fù)合片的合成機(jī)理進(jìn)行了分析。相比較于常規(guī)的復(fù)合片，由傳統(tǒng)復(fù)合片的兩層結(jié)構(gòu)變成三層結(jié)構(gòu)，由一面滲透變?yōu)閮擅鏉B透。碳化硅和金剛石在界面處發(fā)生了強(qiáng)烈的化學(xué)鍵合，生長(zhǎng)成為高熱穩(wěn)定性的金剛石-SiC鍵合結(jié)構(gòu)模式。
[Abstract]:Polycrystalline diamond composite (polycrystalline diamond compact,PDC) is a composite material formed by the thin layer of polycrystalline diamond bonded on the matrix of cemented carbide by metal or non-metallic binder. Usually, cemented carbide substrates and diamond powder are assembled into molds sintered under high temperature and high pressure. The synthesized composite not only has high wear resistance, high hardness and thermal conductivity of diamond polycrystalline, but also has high toughness, weldability and strength of cemented carbide. It is widely used in oil drilling, coal mining, geological drilling, cutting tools and so on. In this paper, the mould structure of the traditional polycrystalline diamond composite sheet is improved: (1) dolomite is used to replace the pyrophyllite inside the pyrophyllite, (2) the cubic boron nitride is replaced by the salt tube as the pressure transfer medium for the high pressure reaction. (3) three-layer metal cup is used to replace the traditional metal foil structure. The high heat-resistant polycrystalline diamond composite for 桅 19mm drilling was successfully synthesized by means of Co and Si powder melt permeation catalysis with a hinged six-sided top press of 63600T. The synthetic process was determined as follows: synthesis pressure 5.5-7 GPA, synthesis temperature 1650 鈩

本文編號(hào)：2413547