共查询到20条相似文献,搜索用时 0 毫秒
1.
Yu. G. Tkachenko V. I. Kovtun V. F. Britun D. Z. Yurchenko G. A. Bovkun 《Powder Metallurgy and Metal Ceramics》2005,44(7-8):407-414
The influence of deformation pre-treatment (milling in a planetary mill and shock-wave treatment) of B4C powders of different size composition on their structure as well as the structure and mechanical properties of samples that
have been hot-pressed from these powders is investigated. It is shown that treatment by shock waves produces a substantial
change in the structure of the powders, and this tends to increase the mechanical properties of the polycrystalline cakes.
__________
Translated from Poroshkovaya Metallurgiya, Nos. 7–8(444), pp. 118–127, July–August, 2005. 相似文献
2.
Shipilova Larisa A. Shipilova Vitalii Ya. 《Powder Metallurgy and Metal Ceramics》2002,41(3-4):147-149
How the structure of electrically conducting ceramic composites in the SiC B4C system is formed has been studied. The mechanical and electrophysical properties have been investigated as a function of the ratio of the components and the sintering conditions. 相似文献
3.
4.
5.
Shirshendu Chakraborty Debashish Debnath Azizur Rahaman Mallick Probal Kumar Das 《Metallurgical and Materials Transactions A》2014,45(13):6277-6284
ZrB2-SiC composites were hot pressed at 2473 K (2200 °C) with graded amounts (5 to 20 wt pct) of SiC and the effect of the SiC addition on mechanical properties like hardness, fracture toughness, scratch and wear resistances, and thermal conductivity were studied. Addition of submicron-sized SiC particles in ZrB2 matrices enhanced mechanical properties like hardness (15.6 to 19.1 GPa at 1 kgf), fracture toughness (2 to 3.6 MPa(m)1/2) by second phase dispersion toughening mechanism, and also improved scratch and wear resistances. Thermal conductivity of ZrB2-SiC (5 wt pct) composite was higher [121 to 93 W/m K from 373 K to 1273 K (100 °C to 1000 °C)] and decreased slowly upto 1273 K (1000 °C) in comparison to monolithic ZrB2 providing better resistance to thermal fluctuation of the composite and improved service life in UHTC applications. At higher loading of SiC (15 wt pct and above), increased thermal barrier at the grain boundaries probably reduced the thermal conductivity of the composite. 相似文献
6.
Metallurgist - Powder mixtures containing copper, boron, and iron were deposited on flat steel billets via nonvacuum electron-beam cladding to form surface layers of increased thickness. The... 相似文献
7.
Grigor'ev Oleg N. Prilutskii É V. Trunova Elena G. 《Powder Metallurgy and Metal Ceramics》2002,41(3-4):142-146
The W2B TiB2 B4C ceramics studied were hot-pressed from composite powders synthesized by thermal reduction of boron carbide. The resulting materials have a skeleton structure with a boron carbide binder when the B4C content is high and an inclusion-matrix structure when the B4C content is low. The grain size varies from 5 to 20 m, depending on the preparation conditions. The composite has a hardness of 17.5-20 GPa with a strength in the range 500-1000 MPa. 相似文献
8.
不含Ca和B,含Ca(0.0026%Ca)和含Ca-B(0.0027%Ca和0.0045%B)的3种无取向硅钢(/%:0.004~0.006C、1.31~1.38Si、0.34~0.41Mn、0.004S、0.027P、0.36~0.41Als、0.0022~0.002 8T[O]、0.004 8~0.0060N)由6.5 kg真空感应炉冶炼,锻成70 mm扁坯,热轧成2.5 mm板,950℃常化后冷轧成0.5 mm板,在30%H2+70%N2气氛经920℃ 3 min退火,炉冷。试验结果表明,无取向硅钢中进行钙处理,钢中可形成CaO·6Al2O3和CaS,有效抑制了MnS的析出,有利于退火冷轧板晶粒长大。复合添加ca和B的退火冷轧板中未发现BN;含0.0026%Ca无取向硅钢退火冷轧板具有最强的{100}面织构和Goss织构组分,含0.0027%Ca-0.0045%B无取向硅钢退火冷轧板具有最弱的{112}<110>织构组分。3炉试验钢中,钙处理的0.0026%ca无取向硅钢退火冷轧板的综合磁性能最好,铁损P1.5/50和磁感应强度B50分别为4.32 W/kg和1.764 T。 相似文献
9.
Russian Journal of Non-Ferrous Metals - In this study, TiC-reinforced NiCrBSi matrix composite materials were produced using the hot pressing powder metallurgy (PM) technique. The effect of the... 相似文献
10.
Porozova S. E. Kul’met’eva V. B. Pozdeeva T. Yu. Shokov V. O. 《Russian Journal of Non-Ferrous Metals》2021,62(2):226-232
Russian Journal of Non-Ferrous Metals - A comparative analysis of agglomerates obtained by spray drying and granulation methods, as well as consolidated materials based on them, has been carried... 相似文献
11.
试验低碳贝氏体钢(/%:0.08C,0.11~0.13Si,1.10~1.20Mn,0.008~0.009P,0.002S,0.21~0.23Ni,0.020~0.021Ti,0.003~0.004Nb,0~0.0010B,0.000 7~0.0008O,0.0031~0.0033N)由50kg真空感应炉熔炼,轧成45mm钢板,并经930℃淬火,610℃回火。研究了0.0010%硼对780 MPa低碳贝氏体钢45mm板组织和力学性能的影响。结果表明,硼可显著提高试验钢的淬透性,不含硼试验钢淬火后得到粒状贝氏体,0.0010%硼试验钢淬火后得到板条贝氏体。硼明显改善试验低碳贝氏体钢的力学性能,含0.0010%硼试验钢淬、回火后的抗拉强度834MPa和屈服强度771MPa远高于不含硼试验钢的抗拉强度702MPa和屈服强度591MPa,实际生产中应加入适量硼可使低碳贝氏体钢得到板条贝氏体。 相似文献
12.
The bahavior of boron with different degrees of purity, fineness, and crystal structure perfection during nitriding at high temperature is studied by electron microscopy, x-ray diffraction, and chemical analysis. The effect of additives (Li2CO3, H3BO3, and NH4Cl) on boron nitride synthesis is studied. A marked reduction is established in the temperature for forming a highly-ordered boron nitride structure on introducing additives. The chemistry of the amorphizing effect of ammonium chloride on the crystal structure of boron is suggested. 相似文献
13.
14.
15.
Tkachenko Yu.G. Yurchenko J.Z. Britun V.F. Vasylkivska M.A. 《Powder Metallurgy and Metal Ceramics》2019,57(9-10):542-550
Powder Metallurgy and Metal Ceramics - The paper examines how the conditions of activation preprocessing (dry and wet grinding) of B4C–Al and SiC–Al powder mixtures in a planetary-ball... 相似文献
16.
17.
18.
19.
Eliseev A. A. Utyaganova V. R. Vorontsov A. V. Ivanov V. V. Rubtsov V. E. Kolubaev E. A. 《Russian Journal of Non-Ferrous Metals》2020,61(5):517-522
Russian Journal of Non-Ferrous Metals - Nowadays prototyping and additive manufacturing of objects are the most promising trends of development. As opposed to more precise powder methods,... 相似文献
20.
硼对奥氏体耐热钢 TP347H 热加工性、组织和力学性能的影响 总被引:1,自引:0,他引:1
试验钢以超临界锅炉用奥氏体耐热钢TP347H(%:0.07C、17.98Cr、10.78Ni、0.70Nb、0.0267N)为炉料,用25 kg真空感应炉在氩气保护下熔炼,并加入0~0.16%B.结果表明,当加B量≥0.02%时,试验钢奥氏体晶粒明显粗化,1 200~950 ℃锻造时锻坯开裂.当加B量约0.01%时,奥氏体耐热钢TP347H具有最佳的综合性能:钢的室温抗拉强度为615 MPa;750℃,120 MPa钢的持久寿命为230 h,伸长率为42%. 相似文献