بررسی اثر مقدار پودرهای سرامیکی zrb2-zrc-sic بر چگالی نسبی و مقاومت به اکسیداسیون کامپوزیت c/c-zrb2-zrc-sic ساخته شده با پارچه کربنی و نمد به روش سینتر بدون فشار

ﮐﺎﻣﭙﻮزﯾﺖﻫﺎی ﭘﺎرﭼﻪ ﮐﺮﺑﻨﯽ و ﻧﻤﺪ ﺗﻘﻮﯾﺖ ﺷﺪه ﺑﺎ ﺳﺮاﻣﯿﮏﻫﺎی ﻓﻮق دﻣﺎﺑﺎﻻ ﺑﻪ دﻟﯿﻞ وزن ﮐﻢ آنﻫﺎ در ﻋﯿﻦ ﺣﺎل ﺧﻮاص ﻓﯿﺰﯾﮑﯽ، ﻣﮑﺎﻧﯿﮑﯽ و ﻓﺮﺳﺎﯾﺸﯽ ﭘﯿﺸﺘﺎز آنﻫﺎ در ﺻﻨﻌﺖ ﻫﻮاﻓﻀﺎ ﻣﻮرد ﺗﻮﺟﻪ ﻫﺴﺘﻨﺪ. در اﯾﻦ ﺗﺤﻘﯿﻖ ﮐﺎﻣﭙﻮزﯾﺖﻫﺎ از ﭘﺎرﭼﻪ اﻟﯿﺎف ﮐﺮﺑﻦ و ﻧﻤﺪ و رزﯾﻦ ﻓﻨﻮﻟﯿﮏ ﺑﻪ ﻋﻨﻮان زﻣﯿﻨﻪ و از ﺗﺮﮐﯿﺐ ﭘﻮدرﻫﺎی sic ،10 :zrc ،76 :zrb2: 10 درﺻﺪ وزﻧﯽ ﺑﻪ ﻋﻨﻮان ﺗﻘﻮﯾﺖ ﮐﻨﻨﺪه وb4c : 4 درﺻﺪ وزﻧﯽ ﺑﻪ ﻋﻨﻮان ﮐﻤﮏ ﺳﯿﻨﺘﺮ اﺳﺘﻔﺎده ﺷﺪ. ﭘﻮدرﻫﺎی ﺳﺮاﻣﯿﮑﯽ ﺑﺎ درﺻﺪ وزﻧﯽ 25، 50 و 75 درﺻﺪ ﺑﻪ ﻻﯾﻪﻫﺎی ﭘﺎرﭼﻪ ﮐﺮﺑﻦ و ﻧﻤﺪ ﭘﺎﺷﯿﺪه ﺷﺪ و ﺑﻪ ﻣﻨﻈﻮر ﻣﻘﺎﯾﺴﻪ، ﻧﻤﻮﻧﻪﻫﺎی 100 درﺻﺪ ﭘﻮدر ﺳﺮاﻣﯿﮑﯽ و 100 درﺻﺪ ﭘﺎرﭼﻪ و ﻧﻤﺪ ﺑﻪ ﻋﻨﻮان ﻧﻤﻮﻧﻪ ﺷﺎﻫﺪ ﺳﺎﺧﺘﻪ ﺷﺪ. ﻧﻤﻮﻧﻪﻫﺎ ﭘﺲ از ﺧﺸﮏ ﺷﺪن ﭘﺮس ﺷﺪه و ﭘﺲ از ﻋﻤﻠﯿﺎت ﺣﺮارﺗﯽ از ﻓﺮآﯾﻨﺪ ﺗﻔﺠﻮﺷﯽ ﺑﺪون ﻓﺸﺎر اﺳﺘﻔﺎده ﺷﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﺑﺎ اﻓﺰاﯾﺶ درﺻﺪ ﭘﻮدر، ﭼﮕﺎﻟﯽ و ﺟﻤﻊ ﺷﺪﮔﯽ ﻧﻤﻮﻧﻪﻫﺎ اﻓﺰاﯾﺶ ﯾﺎﻓﺘﻪ ﮐﻪ ﺑﯿﺶﺗﺮﯾﻦ ﭼﮕﺎﻟﯽ ﻣﺮﺑﻮط ﺑﻪ ﻧﻤﻮﻧﻪ ﻓﺎﻗﺪ ﭘﺎرﭼﻪ ﮐﺮﺑﻨﯽ و ﻧﻤﺪ ﺑﺎ ﭼﮕﺎﻟﯽ ﻧﺴﺒﯽ 98/5 ﺑﻪ دﺳﺖ آﻣﺪ. ﻫﻤﭽﻨﯿﻦ ﺗﺨﻠﺨﻞ ﻇﺎﻫﺮی ﺑﺎ اﻓﺰاﯾﺶ درﺻﺪ وزﻧﯽ ﭘﻮدر ﮐﺎﻫﺶ ﭘﯿﺪا ﮐﺮده ﮐﻪ ﮐﻢﺗﺮﯾﻦ ﻣﯿﺰان ﺗﺨﻠﺨﻞ ﻇﺎﻫﺮی ﻧﯿﺰ ﻣﺮﺑﻮط ﺑﻪ ﻧﻤﻮﻧﻪ ﻓﺎﻗﺪ ﭘﺎرﭼﻪ ﮐﺮﺑﻨﯽ و ﻧﻤﺪ ﺑﺎ ﻣﻘﺪار 0/5 درﺻﺪ اﺳﺖ. در اﯾﻦ ﭘﮋوﻫﺶ ﻣﺸﺨﺺ ﮔﺮدﯾﺪ ﮐﻪ ﮐﻢﺗﺮﯾﻦ ﻧﺮخ اﮐﺴﺎﯾﺶ ﺧﻄﯽ ﻣﺮﺑﻮط ﺑﻪ ﻧﻤﻮﻧﻪ ﺣﺎوی 75 درﺻﺪ ﭘﻮدر ﺳﺮاﻣﯿﮑﯽ در ﮔﺮوه ﭘﺎرﭼﻪ ﮐﺮﺑﻨﯽ ﺑﺎ مقدار mm/s 10^-2× 3/17 و ﻧﻤﻮﻧﻪ ﺣﺎوی 75 درﺻﺪ ﭘﻮدر با مقدار mm/s 61×10^-2 /3 در ﮔﺮوه ﻧﻤﺪ اﺳﺖ.

investigating the influence of zrb2-zrc-sic powders amount on density and resistance to ablation of c/c-zrb2-zrc-sic composite built of carbon fabric and felt developed by the method of pressureless sintering

as a result of their low weight and significant physical, mechanical and ablation behaviors, the carbon fabric composites and reinforced felt with ultrahigh temperature ceramics (uhtcs) have become the focus of aerospace industries. in this research, carbon fabric composites and resin have been used as matrix and the combination of zrb2 76 wt%, zrc 10 wt%, sic 10 wt% powders as reinforcement and b4c 4% powder has been utilized as additive the mixture of mentioned powders with weight ratio of 25, 50, 75 precent was splashed on the carbon fabric and felt layers. for comparison, samples of 100% ceramic powder and 100% carbon fabric and felt were made as control samples. when the samples become dried up, they were pressed and sintered by pressureless sintering method. the results indicated that increasing the amount of powders led to samples density and shrinkage increase. the highest density is related to the sample without carbon fabric and felt with a relative density of 98.5. also, the porosity decreased with the increase in the weight percentage of the powder, and the lowest porosity is related to the sample without carbon fabric and felt with a value of 0.5%. in this research, it was found that the lowest linear oxidation is related to the sample containing 75% ceramic powder in the carbon fabric group with a value of 3.17×10-2  ( mms )  and the sample containing 75% powder with a value of 3.61×10-2 ( mms ) in the felt group.