M.Iqbal
,
M.A.Shaikh
,
M.Ahmad
,
K.A.Shoaib
材料科学技术（英）
Experimental results of the investigation on the hardness of two Al-Zn-Mg alloys [Al-10.0 Zn-4.0 Mg and Al-8.5 Zn-3.0 Mg (wt pct)] aged in the temperature range 60 similar to 310 degrees C for different intervals of time from 1/4 h to 168 h are presented. Both the alloys were found to show identical behaviour of hardness with ageing time. Alloy with higher Zn and Mg content had higher hardness than the alloy with lower solute content. There were three ranges of temperature in which different types of precipitates formed and affected the hardness. Some of the grain boundaries were found to migrate and precipitate free zone has been observed.
关键词:
S.K.Durrani
,
J.Akhtar
,
M.Ahmad
,
M.J.Moughal
材料科学技术（英）
Particle size, textural and surface characteristics influence some major technological properties of high siliceous aluminosilicate zeolite and sillicoaluminophosphate (SAPO) microporous materials. A comparative study was furnished for measuring surface characteristics, particle size and particle size distribution using particle size analyzer (PSA) and scanning electron microscope (SEM). The PSA is capable of measuring particle diameter in micron range. The results of these techniques for estimation of particle size were compared and correlated statistically. Student t-test and variance ratio test (F-test) methods were performed for the significance of results by the analysis of variance (ANONA) and multiple-range tests. Textural and surface characteristics were evaluated by Brunauer, Emmett & Teller (BET) volumetric technique and v-αs plotting method. The textural results shows that the external surface area and micropore volume of microporous materials were higher than those of the high siliceous zeolites and its zeotype materials.
关键词:
Synthesis
,
null
,
null
,
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