多孔tizrnb的制备及其孔隙影响因素的研究

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1、中文摘要本文通过真空粉末烧结制备了多孔TiZrNb合金，采用图像分析法对其孔隙特征进行分析，从而研究了各因素对烧结制品孔隙的影响。并通过SEM、XRD、弯曲测试等手段和方法对烧结制品的物相组成、显微组织、力学性能等进行了分析。结果表明：随着压制压力的增大，烧结产物孔隙率和平均孔径下降，孔的圆整度上升。烧结时间越长，烧结产物孔隙率、平均孔径都越小，圆度越大。这种影响在5h以前比较明显。烧结温度在1000。C至1300"C范围内，对孔隙率的影响趋势是随着温度的提高，孑L隙率逐渐减小；对孔径的影响是先增大后减小，1100"C是个转折点。烧结温度对于孔隙圆度的影响是随着

2、温度上升，圆度上升，在1200。C左右，孔隙的圆度已经达到一个极值状态。造孔剂NH4HC03的添加能有效改变烧结产物的孔隙率和孔径大小，在添加20％质量分数的NH4HC03后，烧结产物孔隙率达到40％以上，大孔隙孔径在几百微米左右。随着造孔剂添加量的增加，孔隙率和孔径都增大，圆度下降。压制压力为120MPa、烧结温度为1200。C、烧结时间为5h时，TiZrNb合金的孔隙率为44．04％，其显微组织为近p型多孔钛合金，杨氏模量为17．9GPa，抗弯强度为264．5MPa，布氏硬度值为153HB。关键词：多孔TiZrNb合金图像分析孔隙特征13相ABSTRACTI

3、nthispaper，powdermetallurgytechniquewasemployedtoprepareporousTiZrNballoy．Theporecharacteristicswereinvestigatedbytheimageanalysistechnology,thenthefactorseffectingontheporewerestudied．Opticalmicroscope，Scanningelectronmicroscope(SEM)andX—raydiffraction(XRD)wereadoptedtOanalyzethemic

4、rostructure，andmorphologyofthealloy．BendingandhardnesstestwereemployedtOevaluatethemechanicalpropertiesoftheporousTiZrNballoy．Theresultsshowasfollows：Theporosityandthediameteroftheporesinthealloyweredecreased，andtheroundnessoftheporesbecamemoreperfectwiththepressureincreasing．Thelong

5、erthesinteringtime，thesmallertheporosityandtheporediameter,andtheroundertheporeswere．Thiseffectwasapparentwhensinteringtimewaslessthan5hours．Whenthesinteringtemperatureincreasedbetween1000℃and1300℃，theporosityofporousalloydecreased．Thediameterofporesbecamebiggerastheincreasingofsinte

6、ringtemperatureuntilitreached1I00"C，afterthenthediameterofporesdecreased．Theporesofalloysinteredat1200"(2possessedthehighestroundness．TheeffectofNH4HC03ontheporecharacteristicswassignificant．Theporosityofthealloypreparedwith20％NH4HC03waswellabove40％，andthediameteroflargeporesofthisal

7、loywasmorethan200“m．WiththecontentofNH4HC03increasing，theporosityandporediameterbecamelarger,andtheporesbecamerounder．TheporouslB-TiZrNballoypreparedundertheconditionof20％NH4HC03，120MPapressure，1200"(2sinteringtemperature，5hsinteringtimehadfavorablepropertieswith44．04％porosity,264．5M

8、Paflexuralst