【摘要】 合金线收缩变化率dl/dτ是铸件产生热裂缺陷的重要因素。作者为了测试受阻收缩状态下各瞬间的自由收缩量及热裂力和热裂温度,改型设计了双试棒合金热裂一线收缩仪。文中详细介绍了仪器构造原理、结构特点,工作状态,测试精度,自记能力等。并利用该仪器做了十种合金的试验,对热裂形成机理做了进一步探讨和分析。更多还原

【Abstract】 Changeability rate (dl/dr) in linear contraction of alloy is an important factor to form hot tear for castings. In order to measure the instantaneous linear contraction at free and hindered state, force and temperature of hot tear of alloy, we have design the twin bar tester of hot tear條inear contraction for alloy and the changeability rate (dl/d-r) in free linear contraction acted as parameter in checking the amount of tendency to hot tear.In this paper,the basic principles of tester’s structure,its working state,test accuracy, registration capacity,reappearace, etc.are presented in detail.The tester has been used to investigation and summarily analyse the ten alloys.The mechanismthat would form the hot tear of alloy was studied still further.更多还原