CAJ | 학술논문

针对 W-Ni-Mn 合金难以烧结致密化的问题，在传统氢气烧结工艺的基础上，发展新型氢气烧结工艺，使90W-4Ni-6Mn合金的相对密度达到98.32%，但仍未达到全致密，并存在部分形状不规则的孔隙和锰的氧化物。为使合金能够烧结全致密，本文再次开发了一种新的真空-氩气烧结工艺，使90W-4Ni-6Mn合金的相对密度高达99.82%，近乎全致密。对合金进行力学性能测试，并利用扫描电镜(SEM)观察其微观结构和断口形貌，结果表明：90W-4Ni-6Mn 合金的抗拉强度和伸长率均随预烧结保温还原时间延长而增大，在100 min 时达最大值，分别为1030.25 MPa和24.2%，此时钨晶粒尺寸为6.2μm。经分析，90W-4Ni-6Mn合金的优异性能主要得益于烧结密度的提高和晶粒尺寸的细化。
침대 W-Ni-Mn 합금난이소결치밀화적문제，재전통경기소결공예적기출상，발전신형경기소결공예，사90W-4Ni-6Mn합금적상대밀도체도98.32%，단잉미체도전치밀，병존재부분형상불규칙적공극화맹적양화물。위사합금능구소결전치밀，본문재차개발료일충신적진공-아기소결공예，사90W-4Ni-6Mn합금적상대밀도고체99.82%，근호전치밀。대합금진행역학성능측시，병이용소묘전경(SEM)관찰기미관결구화단구형모，결과표명：90W-4Ni-6Mn 합금적항랍강도화신장솔균수예소결보온환원시간연장이증대，재100 min 시체최대치，분별위1030.25 MPa화24.2%，차시오정립척촌위6.2μm。경분석，90W-4Ni-6Mn합금적우이성능주요득익우소결밀도적제고화정립척촌적세화。
As it is difficult to obtain full densification of W-Ni-Mn alloy during sintering, a novel hydrogen sintering technology has been employed based on the conventional one. The relative density of 90W-4Ni-6Mn alloy reaches 98.32%without full densification, which indicates that there are some irregular pores and manganese oxide remaining. Then, in order to get the alloy densify fully, vacuum-argon sintering process has been developed, by which the relative density of 90W-4Ni-6Mn alloy can be as high as 99.82%, approximately full densification. In addition, the mechanical properties of the sample were tested, as well as the microstructure and fracture morphology were investigated by scanning electron microscope (SEM). The results show that with increasing the holding time of pre-sintering, the tensile strength and elongation increase gradually, reaching the maximum value of 1 030.25 MPa and 24.2%, respectively, when the holding time of pre-sintering is 100 min with the average tungsten grain size only being 6.2μm. It’s concluded that the excellent properties of 90W-4Ni-6Mn alloy stem from the increase of sintered density and refinement of tungsten grain size.