在討論鉛酸蓄電池工業(yè)用板柵合金之前，必須詳細(xì)討論合金的相圖。鉛銻合金中，銻含量不同，合金的凝固點（溫度）不同，若測出鉛銻合金中一系列不同銻含量的凝固點（溫度）作縱坐標(biāo)，合金中銻含量為橫坐標(biāo)作圖，為了研究相圖方便，把合金液（熔融體）固（凝固體）體系中，物理與化學(xué)性質(zhì)以及組成都均勻一致的部分稱為“相”，比如液相、固相。相圖是指各種組成的合金隨溫度變化時其狀態(tài)變化的圖解。在鉛銻合金相圖中，a稱為a固溶體。a固溶體中鉛多銻少，即鉛中熔有少量銻。p 稱為日固溶體，日固溶體中銻多鉛少，即銻中熔有少量鉛。從鉛銻合金相圖中看到，當(dāng)銻含量13 ％時，鉛銻合金的凝固點最低。含銻少于13 緯時，合金從L （液相）溫度降至凝固點時，首先出現(xiàn)a 固溶體，溫度繼續(xù)下降至C/E/D 區(qū)域合金又出現(xiàn)a 相與p 相。
在生產(chǎn)實踐中，板柵需要細(xì)小均勻的晶體。鑄板柵時要保持一定冷卻速度才能得到極細(xì)小晶體粒，。固溶體內(nèi)含銻量隨溫度降低而減少，開始時銻含量有2 .5 % ，繼續(xù)冷卻至含銻量約為0.4 ％的溫度，若冷卻速度過快，Q 固溶體來不及變化就已經(jīng)成了固相，這時。固溶體是不穩(wěn)定的，部分銻以p 固溶體形式在固熔體中析出，同時由于在固相中擴散困難，造成。固溶體與p 固溶體分布不均勻，板柵因之發(fā)脆。另在板耳處（或粗筋處）因合金液量多，冷卻就相對要慢，也容易造成局部銻含量過多，出現(xiàn)“白斑”甚至裂紋。
合金中銻含量降低，出現(xiàn)“熱裂”的趨勢就越大，因此生產(chǎn)的板柵比較脆。這是由于凝固成粗晶粒結(jié)構(gòu)，并含有熱裂紋，并沿著晶粒的邊界分布。低銻合金的熱裂現(xiàn)象是可以避免的，通常添加變晶劑（成核劑）就能消除。
BE discussing before sour industry of lead uses plank grid metal alloy, have to discuss metal alloy mutually in detail diagram.In the metal alloy of lead Ti, the Ti content is different, the freezing point(temperature) dissimilarity of metal alloy, if the freezing point(temperature) that tests to find out a series of and different Ti content in the metal alloy of lead Ti makes Zong to sit a mark, in the metal alloy Ti content for horizontal make diagram by mark, for the sake of research mutually diagram convenience, chase metal alloy liquid(meltdown body) solid(solidify body) system in, physics and chemistry property and constitute all even consistent of part be called "mutually", for example liquid mutually, solid phase.Mutually the diagram means that various metal alloy for constituting changes with the temperature its status change of illustrated manual table.In the metal alloy of lead Ti mutually in the diagram, the an is called a solid dissolve a body.The an is solid to dissolve many Tis of lead in bodies little, namely the Rong in lead has a little amount Ti.The p is called a day solid dissolve a body, the day is solid to dissolve many leads of Ti in bodies little, namely the Rong in Ti has a little amount lead.See from the metal alloy of lead Ti mutually the diagram, be a Ti content 13%, the freezing point of the metal alloy of lead Ti is lowest.When metal alloy declined from L(the liquid is mutually) temperature to freezing point while containing less than 13 latitudes of Tis, appear a first solid dissolve a body, the temperature continues to descend to C|E|D district metal alloy again appear a mutually and the p was mutually.
In the middle of producing and practicing, the plank grid needs small and even crystal.Zhu plank grid would not° until keep certain cooling speed get the smallest crystal grain, .Is solid to dissolve a body to contain the amount of Ti lowers but reduces with the temperature, the Ti content contains 2.5%s while starting and continue cooling to contain the amount of Ti as about 0.4% temperatures, if cool off speed to lead quickly, the Q is solid to dissolve a body too late variety have already become a solid phase, at this time.It is unsteady to is solid to dissolve a body, parts of Tis dissolve a figure type by solid p the Xi is in the solid Rong body and result in due to spreading a difficulty in the solid phase at the same time.Is solid to dissolve body and p solid dissolve a body to distribute asymmetry, because of does the plank grid deliver frailty.Is another the place(or thick Jin place) is at the plank ear because metal alloy liquid the quantity is many, cool off opposite have to be slow, also easily make partial Ti content excessive, appear "white spot" the crack is even.
The Ti content lowers in the metal alloy and appear the trend of "is hot to split" more big, consequently production of plank grid comparison frailty.This is in order to solidifying thick crystal grain structure, and imply hot crack, and along the boundary of crystal grain distributes.The hot crack phenomenon of low Ti metal alloy can avoid, usually add to become a crystal and then can get rid of.
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