简介：Thisstudyaimstoinvestigatetheeffectofthe1-stepquenchingandpartitioning(Q&P)processonthemicrostructureandtheresultingVicker’shardnessof0.3C-1.5Si-1.5Mnsteelbyusingin-situdilatometry,opticalmicroscopy(OM),scanningelectronmicroscopy(SEM),X-raydiffractometry(XRD),andVicker’shardnessmeasurement.Systematicanalysesindicatethatthemicrostructureofthespecimensquenchedandpartitionedat150℃,200℃,250℃,and300℃mainlycompriseslathmartensiteandretainedaustenite.Thedilatometrycurveofthespecimenpartitionedat150℃ispresumablyascribedtotheformationofisothermalmartensite.Intheearlystagesofpartitioningat200℃,thenearlyunchangeddilatationcurveiscloselyrelatedtothesynergisticeffectofisothermalmartensiteformationandtransitionalepsiloncarbideprecipitation.Inthelaterstagesofpartitioningat200℃,theslightincreaseinthedilatationcurveisduetothecontinuousisothermalmartensiteformation.Withfurtherincreaseinpartitioningtemperatureto250℃,thedilatationincreasesgraduallyupto3600s,whichisrelatedtocarbonpartitioningandlowerbainiteformation.Partitioningatahighertemperatureof300℃causesarapidincreaseinthedilatationcurveduringtheinitialstages,whichsubsequentlylevelsoffuponprolongingthepartitioningtime.Thisismainlyattributedtotherapiddiffusionofcarbonfromathermalmartensitetoretainedausteniteandcontinuousformationoflowerbainite.

简介：ThemicrostructuralchangesofFe83Si4B13amorphousmotheralloyduringtheheatingprocesswereinvestigatedbyLaserScanningConfocalMicroscopy（LSCM）,andthephasetransformationwasdeterminedbytheThermo-Calccalculations.ThedifferencesinthemeltingpointsmeasuredbyDifferentialScanningCalorimetry（DSC）andLSCM,andthoseobtainedbyThermo-Calccalculationswerealsodiscussed.ItisfoundthatthemeltingpointsmeasuredbyDSCandLSCMarerelativelysimilar,whereastheonsetandendofthemeltingtemperaturescalculatedbyThermo-CalcsoftwarearehigherthanthosemeasuredbyDSCandobservedbyLSCM.

简介：用滚镀的方法在金刚石表面镀Ni层和纳米Si3N4/Ni复合镀层,用扫描电子显微镜观察金刚石镀前和镀后的表面形貌,用DKY-1型单颗粒抗压强度测定仪测量金刚石单颗粒的抗压强度。用热压烧结的方法得到铁基结合剂金刚石节块,在INSTRON-5569型万能材料试验机上测量节块的抗弯强度,在NMW-1立式万能摩擦磨损试验机上测试节块的耐磨性。结果表明：在金刚石表面镀Ni层和纳米Si3N4/Ni复合镀层后,表面镀层均匀,纳米Si3N4/Ni复合镀层比纯Ni层更致密,更平滑,晶粒更细小;纳米Si3N4/Ni复合镀层金刚石单颗粒有更高的抗压强度;纳米Si3N4/Ni复合镀层金刚石铁基结合剂节块有更高的抗弯强度和更优良的耐磨性。